how long till i know if i am pregnant?

[angiemak21]

last night my boyfriend ejaculated in me, it was my next to last day of my cycle,15 hrs after ejaculation i took a pregnany test and it came up neg. could i still be preg? or did i take the test to early?

[magic-8.ball]

"Ask Again Later".

(Yes, you tested too early)

[daycare mom]

Does the next to last day of your cycle mean you are due to start your period tomorrow? If so, you are most likely not pregnant, but it is way too early for a pregnancy test. you need to wait about ten days from the day you had unprotected sex before a pregnancy test would be positive. You are most likely to get pregnant if you have unprotected sex 10-15 days after the first day of your period, but you could get pregnant if you have sex before that or after that depending on when you ovulate. It sound like you are not wanting to be pregnant, so I would suggest using some form of birth control until you are ready to be a mom. Good luck.

[maryheather]

Yes, you did test too early.  If I understand correctly, today would be the last day of your cycle, which would mean that you're supposed to start your period tomorrow.  You will have to wait until at least tomorrow to test, preferrably the next day.  However, although no one can tell you if you're pg., most women ovulate anywhere between day 11 and day 17.  (I think 14 is average??? some one else may know more about this than me.)  If this is the case with you, then today would be day 28(give or take a day) and it is highly unlikely that you're pregnant.  
You should always use a condom, though.  Remember that pregnancy is just one thing that can happen when you have unprotected sex.

Some people on this forum don't like it when that question is asked, and I didn't want you to feel like no one had seriously tried to answer your question.

Just be careful.

[babyblues7]

It is very unlikely you are pregnant if it was 2 days before your period is due, even though most things are possible. you would have to wait a week or so to get a positive result if you are pregnant. i also agree with the above comments....

[Learner1]

I would also say unlikely u r pregnant!  Cant test til you've actually missed a period..Def go see ur doc & get on a form of birth control & use condoms to keep urself from asking a STD question!  =)  Good luck 2 you!

[angiemak21]

i am sorry. i guess i don't know my body and cycles at all, the only thing i know is when i start. so i guess i need to rephrase the question. i am on my last day of my period, and my boyfriend andi are planning on starting a family, we are like 23 and getting married.

[baby4Staci]

WOW you have everyone confused.. HAHAHA

The first day of your Last menstral period is considered CD 1  If you have a 28 day cycle you are most fertile around CD 14.  Your boyfriends sperm can live for 72 hours inside of you when he ejaculates.  If you and your boyfriend are interested in conceiving a child, you should do some research on fertility methods.. it will be the easiest way to keep track.  

A pregnancy test will work 10 days after fertilization and usually no sooner..

Good luck!!

[lorriep]

Also, you can buy cheap ovulation kits over the counter that
can help you determine the days you are most fertile.

[mandymoo1983]

were do people get there information from these days.

[IWantToBeAMom]

You won't get an accurate reading on a hpt until you are due for your NEXT period.  If you had sex last night and are on the last day of your period, then you're going to be ovulating in the next week or so.  So, if you have long-living sperm and an early ovulation then you could get pg, but you won't be able to take a test until you're due for your next period.

A textbook cycle works like this:
Cycle Day 1 - the day you start your period
Cycle Day 14 - ovulation
Cycle Day 28 - the start of your next period, a.k.a. Cycle Day 1 of your next cycle.

However, CD 14 is only the textbook body and there are many variations to it.  You might ovulate early, you might ovulate late... the only way to know for sure is to watch for bodily signs and/or take your BBT everyday and chart it.  You can use www.google.com to research it too.  Type "ovulation" or "menstral cycle" and read, read, read.   There is mountains of information, more than we could ever type.  But the basics are above.

Good luck!!

[babyblues7]

how long is your average cycle? that will give you a better insite on the times to have sex. for example i'll do my cycle
28days ovulation around day 14, best to have sex from day 10-15. it does vary from person to person as everyone is different!!! if you are trying to conceive it is better to know a lot about your menstural cycle. although from my own experience you can read a little to much into it and get your hopes up to much! if you want help i'd be happy to help!!!

[AndiJ78]

Chances are pretty slim you are pg. Normally I wouldn't say this, but maybe you guys should take some time and really think about it. Start tracking your cycle, educate yourself about your body and how your cycle works, and make sure you are in a place emotionally and financially to care for a child. It is a major commitment, I had my first at 23. By that time I had been with my dh for 4 years, married for 18 months, and it was a major adjustment.

Good luck to you and your spouse and your future plans for a family.

Andi

[daycare mom]

I agree with Andi. I had my first at 22, and we thought we were ready, but it was really hard. starting a family is financially draining. especially if you are also trying to save money for a wedding. I would spend the next several months reading up on fertility, and charting your cycles so that when you are ready, you will know what is ghoing on with your body, and hopefully you will conceive more quickly especially if you can pinpoint when you ovulate. good luck.

[babysmomma]

I am a mother of three and I am trying for my last child and I have doctored with a excellent doctor and the stuff you read in books and hear from idol chit chat are totally bogus.  My doctor has informed me that you can get pregnant at any point in your cycle especially if you are like me and produce more then one egg a cycle.  So no not everyone does know what they are talking about.  I by the way for my last daughter got pregnant when I was one day off my period.  Don't believe everything you hear.

[babysmomma]

I might be pregnant right now and don't even know it.  But as I said before I know that my doctor told me if you have this condition you can get pregnant anytime through out your cycle even during your period I know it is sick to think about it but anything is possible.  We are trying for my last child now after coming off protection and I got pregnant three years straight in a row all 6 monthes or shorter then that.  Anything is possible. And I do agree if you are not quite ready for the expence and the continous care you must give then think twice because you can not change things once you have a baby.  Please make sure you are financially and physically ready.

[cmcdan]

I am going to recommend you buy "Taking Charge of Your fertility".  It is a book by Toni Weschler, MPH.  It helps in clearly teaching you about your body, cycle and how to get pregnant.  Most women are only fertile for 24 hours, a very short window to become pregnant.  To go by the fact that on day 14 you will be ovulating is a huge estimation.  This book shows you how to chart your body, in turn, telling you when you are ovulating.  Women are so sporadic in their cycles, these figures are very vague.  I highly reccomend this book to anyone who truly wants to know how their body works.  It is good for teen girls to learn to simply know their bodies and their cycles.  This type of charting has truly helped women and physicians figure out other issues as to why someone cannot get pregnant.

Good luck...I hope that you are eventually successful in having a baby of your own.

[Racqell]

I Am Not  having signs of implantion spotting but i also have thyroid diease so my periods are all missed up when can i take a preg. test for most accurate results?

[xmtmgn1728x]

you took the test way too early.wait until you are supposed to start your next period. if you miss it or its late take a pregnancy test. or better yet go to your doctor since you mentioned that you have thyriod diease get a blood test done its 100% accurate but wait.good luck and i hope you get the results you are looking for.

[blueeyes085203]

ok, i started my last period on June 21st. me and my well x boyfriend now, had been having sex up until the nite b4 i started......i have not started my period yet.....should i start panicking now or later....2 day is July 24th

[midnightstar1981]

hiya well if you have a 28 day cycle that means you would of been due to start your next cycle 19th of july and its now the 31st of july if you still aint had a cycle i suggest you do a test now......but stress can also cause a delay in your cycle good luck

[honey 77]

i want to know if i could be pregnant
i was on my 3rd day of my period me and my b/f had sex
so could i be pregnant

[softballerchik1]

I had sex during my period and my period oddly just stopped the next day. It happened on a Friday night and by the time i got back to my house Saturday I had stopped. I started taking birth control that Sunday night but i kept forgetting to take a second dose until like Wednesday or Thursday night. We did not use a condom. My period according to the pack of pills should have started Wednesday. I have started spotting a little bit today. Do you think I am pregnant? There is also a good chance that the reason i started spotting was because of my mom and me fussing. What do you think?

[alexdd]

i had sex like 2 weeks before my period. but my boyfriend pulled out before he cummed. is it possible he could have like pre cummed or something and a chance for me to be pregnant

[samiizzzz]

How long till i know i am preg????

[samiizzzz]

please try and conntact me asap :D

fankoooo

[marshie]

My boyfriend and I had unprotected sex, the next day I got the "morning after pill". Last night,(roughly two days after taking the "MOP"), the condom broke, however he did not ejaculate. Should I be getting this pill again?

[ashley16]

me n a guy  had sex with a condom n it brok i was off my period for 2-3 days i only get it for 7 days n i am kinda worried i am prego..what do you think?  I am 16 and i dont know what to do...please help me..  Thanks Ashley

[LyssaLou]

Ok. I had intercoarse 7 days ago. I am not on my period because I get mine only every 3 months. Because I would get cramps so bad so now I am on birth control, but, I take 3 packs in a row before getting my period.  Also I have been missing alot of pills which isnt good for this time.. lol..  So I am wondering how long I have to wait before I take a pregnancy test..  right now I am only on my second pack of pills.. which means I would have to wait over a month before my next period.. and I cant wait that long I need to know now. It was a mistake.. I had been drinking.. and I am worried, and I will not be able to feel any better about this until I know. So hopefully someone can tell me, how long I have to wait to take a home pregnancy test. I do not want to go to the docs yet, because I dont want any one to know.. also, I dont have a family doctor at this time. !! please help! thanksss...

[nikki126]

when i was preganant a year ago i bled 2 times in one month it was the following month i found out i was  6 weeks pregnant i had back pains and all the same things r happining again do u think it is coincidence or do u think it is possible that i am pragnant?

[lexi268]

me and my boyfriend had sex like two weeks ago jus before my period was dued it came one day after, i had really bad cramps and i felt real sick.. sicker than usual... we had sex again right after my period was finished... and now i think am pregnant... could i be??

[little_town_girl]

on april 21, me and my boyfriend had unprotected sex, and yes we are trying! now i am having all of the symptoms my breasts are very sore, its awful to touch them or even brush my arms against them. i urinate almost every hour to hour and a half, and i sleep SOOO.. much and i have horrible mood swings! but when i take a test only one line shows up and it has been a week. also, i took an EPT test besides a cheap one and the other line faintly started showing up but it took like 10 mins for it to barely even show..do you thing should i wait and take a test at a later time?do you think i am pregnant?please help me!thank you!                          -little town girl.

[BLong88]

i had sex about 2 days ago. i want a baby but my boyfriend don't, he is usually really anul about using a condom, but i have resently found out that i am alergic (allergic) to them. I can't use laytex and hte lamb skins are really expensive, anyhow we didn't use a condom and he is worried i am prego, i wouldn't mind this but for his sake i hope not. i know it was stupid and not something we should have done, but it just did. Anyhow, how long do i have to wait till i can tell. I was reading online and it says even the test that are for sale that say early pregnancy test aren't accuret. So is there another way to test or do i just have to wait?

[BLong88]

i also forgot to add that i get sick from birthcontrol, it gives me the morning sickness simptom

[Kim1989]

there are differnt types of bc other than the pill you kno. you have to wait untill your periods due or till you miss one

[confused_me]

Hi everyone, im very much confused! my last period was May 27-30 2008 (32 days cycle) which normally i got 28 days cycle, this was my first time i had a 32 day cycle, we had sex after my period, then again on June 10th, as i red on the ovulation/fertility calculator i am fertile from 10-16th June, & my ovulation day would be most probably 14th or 15th of June. Now im experiencing this weird feeling, dizzines,cramps,food cravings,bloating,mood swings, i took a test but it showed negative :( ... is it too early for me to take the test?.. my next period will be on 28th June (32 day cycle).

[evthing4reason]

If you normally get a 28 day cycle i would test again in a few day because your last cycle may have just been delayed but sometimes you don't always get a postive right away

[confused_me]

Hi there! thanks for your reply! ... its already 29th of June but still havent got my period yet... i'll do preg. test after some time.

[confused_me]

am crossing my finger!!!.... wish me luck guyz!!! =)

[confused_me]

i took a test 2day and it was clearly ............................................................. POSITIVEEEE!!!! yeyyyy!!!!

[evthing4reason]

Thaat's great!!!!!!!!!!!!!!!!!!!!!!!!!

[shan1234]

hi me and my fiance are trying for a baby and i have been off my period now for 7 days since 29th june and since we have had sex 3 times. on the ovulation calculator and it sez the best time to concieve wud be the 5th-10th july. once had been tonight lol do you think i could be pregnent? i have only been off the pill 3 weeks tho or is it still to early yet?

[Kim1989]

i think it would be to early. besides if you got off your period 7 days ago and lets say you were on your period before that. your period was like what june 25...... conception would occur until Wednesday, July 9, 2008 anyways so your having sex a little early

[shan1234]

thanx 4 ur reply dint think no1 wud answa lol. do ya no how lng it teks 4 u 2 concive wen uv come off the pill?

[confused_me]

Hi,

I came off  to pill 3 months ago... and now, im 7 wks. preggo. :)

But i think it depends upon your body, i was on pill for 2 yrs.

[shan1234]

congratulations thanks 4 replyin i guess im just gunna av to wait n be patient lol thanks agen.

[Worried_happy_scared_me]

help me i am so scared im 18 and i think i might be pregant what should i do

[Kim1989]

TAKE A TEST

[nindi]

Hi, I had sex with my GF 7 Days back.Her period was due to come on next month 5th.But Her period have started 10 days before i.e today.too difficult to distingush b/w Implantation bleeding or normal period.She had taken e-pill after 12 hours of having sex.Please let me know if everyhting is ok???

[Kim1989]

the pill will effect her cycle. she will bleed, spot, have a "period" early, have a period that goes mia. i say shes not pregnant you could always have her take a test

[blondegirl12]

if my boyfriend and i had sex a day before i started my period, is there a chance i can be pregnant? thanks.

[loser275]

Okay I had sex last night and I didn't use protection and My boyfriend wiped the "***" off of his penis but We had sex more than once last night could I be pregnant or am I overreacting ! please reply as soon as possible

[AnxiousGurl]

Ok so since every is asking ..I might as well ask again

if I was at cycle 7 a week after my period is it likely im prego?

[Kim1989]

loser- um yes you can be pregnant. who cares it he wiped teh *** off of his penis. YOU DIDNT USE PROTECTION

anxiousgurl- i responed to your post earlier today

[GUY27]

Okay i had sex with my gf last Monday and she started her period the next day, which was a week early. According to her it was a normal period other than it being early. What is the chance that she could be pregnant? The reason for concern is that we always use a condom and on that night the condom broke while i was in her and we did not realize it until we where done.

[Kim1989]

anytime you have unprotected sex you run the risk of getting pregnant. it all depends. if that was her real period then its not likely it all just depends

[darrenshagger101]

one of my best friends are pregnant and she doesnt know how long till you can take a pregnancey test. how long?

[darrenshagger101]

i need help. my friend is pregnant what should she do , shes only 14 . !!!!!

[clairelou88]

tell her to go see a doctor

[darrenshagger101]

how long untill a pregnacey test will show if your pregnant or not? thanks for gettign back tooo

[Kim1989]

darrenshagger101- how is she pregnant but doesnt kno when to take a test. you kinda have to take a test to find out if your pregnant!!!!you take a test when your periods due or missed

[darrenshagger101]

yeeaah buht she aint too sure of it , buht she cant wait what are the signs of it .?

[Kim1989]

how is she not sure of it?

a missed period is the first sign.

did she miss her period

[tish23]

my bf and i had sex 2days after my period what r my chances of being preg?

[Kim1989]

high somewhat beacsue you were nearing ovulation

[nathila]

i have sex and i really dont know if i am pregnant now i am 3 week and dont have my period can i be pregnant

[Kim1989]

TAKE A TEST!

[navidrosy]

Can I get a pregent? if possible u tell me process. i get marrige 10 years. first pregence i abousoton. what can I get a pregent.

[Kim1989]

its hard to understand with your spelling.


pregnancy*
and i think you mean abortion? thats how its spelt.

there can be a number of different reasons as to why you are not getting pregnant

[juicy828]

my boyfriend and i had sex and it was two days after my cycle and he told me that it was pre com that went in me now im haveing crazy headache feeling sick back hurting alittle milk coming out of my breast please help me understand what could be going on

[Kim1989]

you can get pregnant from precum. if you were pregnant you would not have milk comming out of your nipple at all.

ddi you miss a period

[Joanna86]

Me and my boyfriend had sexual intercourse 8 days ago and he ejaculated in me. Could it show ii was pregnant 8 days later?. would signs of pregnancey show this early??? wb asap please :( need you'r help x thankyouu x

[Kim1989]

no urine hpts would not show our pregnant 8 days later. signs can appear when implantation happens

[rahj]

I have the same question as alexdd. . . . Is it possble to be showing symptoms 2 days after unprotected sex or am i just panicing?

[nassa568]

me and my bf had sex the hole time i had my period could i be prigo and we had sex the hole week after iam 18 and we want a baby plz can u help me we started haveing sex one the 28 of dec. till the 3 of jan. and i hab my period for 3 days could i be prigo today is the 5th of jan.

[Kim1989]

yes you can be pregnant and stop trying for a baby at your age. im 19 and having a baby is VERY hard. go to college. do something with your life. have goals. get married. settle down. have a house. then try for a baby.

and im really emphasizing the college thing if your spelling prego....prigo

[Rijaen]

i want to add to that.. dear you are young to think of having a baby.. the other girl is right. got to school and enjoy life.. you can have babies later. you can have as many as you want.. Life is hard this days...

[Imlost16]

Hello, i am in iraq and my fiance and i had unprotected sex back in october while i was on leave. She is on birth control (shot every three months) and two weeks she went to the doctor and got a pregnancy test and it came up negative. She never has her period because of the bc but a few days ago she said she had her period, and told me that she heard bleeding was a sign that she could be pregnant. Is this possible, could she be pregnant, and if so should i get a paternity test. I love her but i dont know anything about it so i just dont know. PLEASE HELP ME!                                  Pfc. Hunter

[Kim1989]

shes on birth control. and shes been getting her period (and you still will get your period evenwhen your on birth control) and has been getting negative pregnancy test....

shes not pregnant

[teen_latina]

i am 2 weeks and 2 days late  for my period i was suppose to start on the tenth of april and i still havent started. is it to early to take a test or is the time right? what should i do?

[bunney12]

am trying to get pargnant am 22 and am going to get merreyed to my boyfriend how do you know if your pargnant with a bbt  thermometer  and what  are the numbers of a bbt thermometer if you are pargnant this is the frist time i useed a bbt thermometer can anyone help me

[lilangel09]

ME AND MY BF ARE HAVIN UNPROTECTED SEX NEARLY EVERY NIGHT...AND I HAVE ALWAYS HAD IRREGULAR PERIODS,,,AS I WAS A LATE STARTER I DDINT GET MY 1ST PERIOD TILL I WAS 18 IM NOW 21 AND I GET MY PERIOD EVERY 2 WEEKS BUT IM DUE OJN THIS WEEK AND HAVENT CAME ON DO U THINK I COULD B PREGNANT?....ALSO I AM GETTIN HEADACHES WEN I WAKE UP IN THE MORNING I AM BEIN SICK ON A NIGHT TIME ND SUMTIMES ON A MORNING.... MY BOOBS ARE A LITTLE BIT TENDER AND IM GETTIN ALOT OF BACK PAIN AND IM EATING LIKE A PIG ???

[Kim1989]

if your getting your period every two weeks and have been since you got your period...somethings not quite right.

yes you can be pregnant...your having unprotected sex "everynight"

[mommiewannab]

Me and hubby are trying to have a baby. We have been together for six years and we really want a child. We had sex on the 7-8th of July. I started my peroid on the 9th. Can it happen before you start your peroid?  I know this question has been asked numerous times but I didn't want to read through all the post....I wanted a clean cut answer.  Also, throughout the 6 years of dating we have had unprotected and protected sex and I have been off and one birth control. I am a little concerned that I can't get pregnant. Me and my hubby were just talking about how many time he has ejaculated in me and I have never gotten pregnant. I just thought being 25 and young it would be easy to get pregnant.

[Hubba12]

My fiancé and I are trying for our first child. The first day of my last period was July 2nd. And the last day of my period was July 6. We have had sex every other day since then up until the 19th and from then we had sex every day up until now(July 23). How long do you think I should wait to take a test, I took one on the 22nd and it came back negative? Was that too soon???

This is our 3 time trying…:(

[Kim1989]

your supposed to take a test when your periods actually missed. taking a test before then is very likely to give an incorrect answer

you should take a test in about a week

[Hubba12]

Thanks for the advice, I really hope this time it worked...I never imagined that it would be this complicted to have a child.

I will keep you posted if your interested...

[fay15]

my boyfrined nutted in me and i didnt take a test but i been throwin up and feelin sick and its been 3 day

[mandee22]

My boyfriend and I have been trying for two weeks. He ejaculated in me 3 times. I am not suppose to get my period until the 29 of each month when should I go get a pregnecy test?

[Myname_99]

you should take it in e few weeks or a week after ur period ok i neeed help im not pregnat and dont want to be but heres the problum i am sexual active and have 121 percent fretility meaning i have high hormones and the pill the shot and iuds are not a option for me cuz there not strong enough! i tried the patch but it messed with my system and has seriuous medical risks i want to be a mom when me and my boyfreind are ready and after we get married weve been together for two years and are not ready for a child we use condoms but with our combined fertilty rates i dont trusts that that is enough anyone there who can help???????!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[britt741]

ok im 15 and i had my son july 20,2008 when me n my ex first had sex we didnt think nothing about it and we did use a condem  and i still got preggers cuz some of his stuff leaked out in me but i knew i was pregnant the second we got done it was jsut that feeling, so 2 weeks later i took a test it was negative, 3 weeks=negative and all the way up to a month was all negative then when the 2nd month started it was positive so just keep takin a test everyweek even if u do get your period because my period didnt stop till my 3rd trimester

[equilibriumxi]

Hi there!
You all seem to have the same question: "HOW LONG UNTIL I SHOULD TAKE THE TEST?" and "WHEN CAN I GET PREGNANT?". These are very valid questions, and women, it's time to educate yourselves with the answers. First off, a woman has a 20% chance of conceiving in one month. This means that she has about 3-5 days in which she can actually get pregnant.  I suggest that couples go through ovulation kits together and determine when the woman has her highest point of ovulation and when her days are estimated to be and try from there. Go, go, go!

Now, TESTING, the pregnancy hormone is detectable after approximately 4 weeks after conceiving. Not after your period, but after conceiving. This means that 4 weeks post-intercourse that hormone has the ability to be seen. Now because most people cannot keep track of their activity, I usually say take the test 2 weeks to one month after your missed period. The hormone for pregnancy is detectable at 4 weeks, but in all truth, it is most evident at 6-8 weeks after conceiving. Also, should you be taking the test, DO IT IN THE MORNING, first thing when you get up, the hormone is strongest and most concentrated in that first release of urine in the morning.
Good luck everyone.

[equilibriumxi]

And if not many people quite understood that, I recommend taking the test one month after your missed period to determine pregnancy.

[C0W6URL]

DO YOU REALLY WANT TO KNOW IF YOU ARE PREGNANT and is it too early to take a pee test?  Go to your doctor or the er and have them do a blood pregnancy test.  This will tell you almost immediately if you are pregnant, where as you may fail a traditional pee on a stick test until you are well into your second trimester before the hormones are strong enough to get into your urine.  Generally you take a pee test around the week your period should be expected at the earliest.  The best, most accurate test on the market is the clear blue digital.  It told us we were pregnant two months in a row when doctor's test came up neg.  Finally they did a blood test and it came up positive.  I had mirena and lost it in my last week and was in the er and they did a blood pregnancy test because even though it had been 4 days since we lost it, the possibility was there.  We finally located the iud and have gotten rid of it since its more trouble than its worth, but my suggestion is to get an iud since they are 100 times more effective form of BC than having your tubes tied.  Did you know the pill and condoms, both used properly, only have an 85% chance of preventing pregnancy??  Did you also know that the pull and pray method carries an 85% effective rate of preventing as well>??  IF THERE IS A DOUBT IN YOUR MIND THAT YOU AREN'T READY FOR CHILDREN THEN YOU SHOULD GET THE MORNING AFTER PILL.  IT'S EFFECTIVE UP TO 72 HOURS, EVEN THOUGH THEY USUALLY WON'T GIVE IT TO YOU AFTER THE FIRST 48.  IT IS NOT AN ABORTION PILL BTW.  IT'S JUST AN OVERGROWN BC PILL.

[sparks_1301]

me and my boyfriend have been having sex nwarly everyday or every 2 days for 2 weeks after i finished my periods. i have been having pains in my lower back and front like cramping, my breasts have enlarged and i feel ill a lot. could i be pregnant this quickly? my periods are due in a week do i have to wait that long to do a test ???

[ladynelson]

around the first two weeks can yu tell if your pregnant