DNA / Paternity Community
Are ultrasound conception dates accurate?
About This Community:

This patient support community is for discussions relating to DNA/Paternity testing. The purpose of the community is for members to discuss information and share support with members who have questions about DNA / Paternity testing. Topics include when to test, types of tests, cost, reliability, confidentiality, legal issues, and results. All questions and comments posted in the patient to patient forums are provided by individual visitors who are NOT MEDICAL PROFESSIONALS.

Font Size:
A
A
A
Background:
Blank
Blank
Blank
Blank Blank
598 Comments Post a Comment
Viewing 601-616 comments:
Blank
Avatar_f_tn
I AM CONCERNED. I HAD SEX WITH MY BF FROM MAY 13-MAY 26 THEN HAD SEX WITH SOMEONE MAY 28. I HAD MY FIRST ULTRASOUND JUNE 27TH AND I WAS 7WKS1DAY. MY PERIOD WAS ON MAY7TH. IS THERE A POSSIBILTY THE OTHER GUY CAN BE THE FATHER?
Blank
134578_tn?1404951303
It sounds like you were about six days or a week past conception, when you had sex on May 28.  Meaning, you were pregnant when you slept with Mr. May 28.

The reason you can be pretty confident in the ultrasound is that it was early, and the sex with the other guy was after sex with your boyfriend.

If your ultrasound were in your seventeenth week and not your seventh, you would have reason to be nervous, because later on, the margin for error gets larger.  But at 7 weeks 1 day, ultrasounds have a margin for error of not more than about +/- a day.  Your ultrasound points to about May 21-22 for conception.

Also, if you had slept with the other guy before your estimated ovulation date, that would be more iffy, because sperm can live up to 5 days or so in your system.  But since you slept with him after the ovulation date by about, say, 6 days or a week, your egg would have been gone if it had had to wait that long.  (An unfertilized egg does not last for more than 36 hours.)

Blank
Avatar_m_tn
What trimester does 14 week fall on? And can a 14 week dating ultrasound be 4 weeks off.. for example can it say i conceived Jun 26 and really conceived may 23? I am currently pregnant. I took a home pregnancy test may 9 and went into doctors office may 12 they did blood work hcg was 214 .they did ultra sound same day and didnt see anything. Aniway I keep coming in every 2 days and my hcg level started to double. OK this is where I'm going with my story I went in again July 14 for an ultra sound and I was told I was 13 weeks and 2 days and my due date was January 17. My concern is I had sex March 16 with someone  but im going to say march 23 to give it time because you dont concieve (conceive) right away and got back with my spouse April 6 and started having sex April 12 throughout that whole month with my spouse. Is it possible the ultra sound can be 4 weeks off and the father could be mr. March and not my spouse.? By the way I did bleed for 4 days April 2 it felt like a normal period or could it have been implantation? . This Is another  concern THE Ultrasound Is Saying MY Last Period Was April 12 AND I Conceived April 26 When IN Reality MY period Was April 2.. Help Please...so lost and confussed
Blank
134578_tn?1404951303
Hi, jaylee, if an ultrasound in your 14th week is not adding up, it is not surprising.  The margin for error could be +/- a week by then.  But it still sounds like Mr. March is out of reach.  You are due on what date, according to the first ultrasound you had?
Blank
Avatar_m_tn
My first ultrasound July 14 2014 13 weeks 2 days gave me a due date of January 17 2014 my second ultrasound according to measurements I was 19 weeks 4 days which was a 2 day diffrence they l didn't change the due date.. so my due date is still January 17 2015
Blank
Avatar_m_tn
By the way my second ultra sound was on August 25 2014 that's the one that dated Me 19 weeks 4 days
Blank
134578_tn?1404951303
Don't worry, the guy in March is totally out of reach even if your ultrasound were a couple of weeks off.
Blank
Avatar_m_tn
Thank you
Blank
Avatar_m_tn
So there's no way  I conceived on march 26??
Blank
Avatar_m_tn
So there's no way I could have concieved on the 23 of may when ultrasound July 13 dated me 13 weeks 2 days and the  due date  they gave me January 17??
Blank
Avatar_m_tn
Sorry not 26 I meant 23
Blank
134578_tn?1404951303
If you are asking if you conceived in late March, the answer is that it would be too early to produce a pregnancy that had an hCG level of 214 on May 12.
Blank
Avatar_m_tn
Hi there,

I feel like, logically, I know the answer here, but I need to ask anyway to hear someone say I'm right :)

My due date was 12.13.14, I had sex with Man A on 3.5.14, and felt like I ovulated (pinching sensations) on 3.21.14, having had sex with Man B every couple of days leading up to 3.22.14.

I just need to know it's Man B's :)
Blank
134578_tn?1404951303
Unless the due date was given to you extremely late in the pregnancy, it sounds like you did not get pregnant from the sex on March 5.
Blank
Avatar_m_tn
Thanks for your quick response!  The GA was 7 weeks, 2 days on April 28th, my first ultrasound.
Blank
134578_tn?1404951303
In fact, the way it counts out, it sounds like you would have been having a period on March 8.  Was the baby born when expected?
Blank
Avatar_m_tn
I actually ovulated on cycle day 19, so, first day of LMP was 3.3.14...and the baby was born at 37 weeks due to being induced for ICP.
Blank
134578_tn?1404951303
I don't see why you still have a question in your mind, but it is a simple enough matter to do a DNA test if it is bothering you.
Blank
Avatar_f_tn
Hi Annie, Im in need of you're help, I'm currently 36 wks 6days pregnant, my lmp was April 8 2014 it lasted until April 12 but on the 11th of April I had un protected sex with an old friend. He told me he did not ejaculate, on the 15 through 22 of April I was with my current bf, my due date is the 13 of january , I would just like to clear some things up, thank you .
Blank
134578_tn?1404951303
How early in your pregnancy were you given a due date from an ultrasound?
Blank
Avatar_f_tn
I was 22 wks 0 days when I received my first ultrasound .
Blank
134578_tn?1404951303
According to the calculator I usually use, you conceived on April 22 or thereabouts.  Getting this figure from a 22 week ultrasound is a pretty iffy thing to do, however.  Your 11-day (or 6-day if you consider the life of sperm in your system) margin of safety and the possible margin for error in using a 22nd-week ultrasound to date a pregnancy are pretty much the same size, with the big margin for error wiping out the relatively OK margin of safety.  Since your period was when the calculator says it should be, it suggests you did get pregnant too late to have the baby be from Mr. Friend.  But to be absolutely sure and never have to stress about it or wonder, a DNA test is a good idea once the baby is born.
Blank
Avatar_f_tn
Does the day of the week matter like I was with my friend on a Friday and I was with my boyfriend on a Tuesday and now every Tuesday I gain a week for example today I'm 37 wks 0 days . If that makes sense ? Thank you, I really appreciate you're help.
Blank
134578_tn?1404951303
No, not just the day of the week doesn't matter, but the gain doesn't matter either.  Babies can grow at different rates.  The only super reliable ultrasound for determining conception is an early one, like 6 or 7 weeks.  After that, it begins to be +/- a number of days, to the point where when you are at 40 weeks, it could be +/- three weeks.
Blank
Avatar_m_tn
hello, I'm hoping someone can help me out with possible conception date.
the situation is this...my son's (ex) girlfriend is pregnant, but saying the baby isn't his. She has supplied the following details..

she says her LMP was 7 Oct 2014 (which gave me a due date of 13/14 July 2015) and possible conception date around end of october 2014.

Her 1st scan gave her a due date of 22 July 2015, which makes her conception date probably a bit later..

thing is, she slept with my son on 31 oct/1 nov, and this other young man on 15 Oct (when my son was on holiday with us, grr) so she seems quite certain of her dates.
She is adamant this other boy is the father, she lives with the family as a foster-child (its a complicated situation!) So perhaps it is just more convenient to say it is his so as not to potentially lose her home.

but based on every calculation I can make, from LMP-due date, to conception calendar, everything points to a later conception than the 15th by far.

any advice or help, or professional medical/midwifery opinion would be greatly appreciated. Thanks, Annie
Blank
134578_tn?1404951303
How reliable do you think her information is?  Has she shown you or your son her sonogram reports, or is this just all by her telling you things?  How old is your son?

If you have a copy of her first scan, will you look at it and tell me if it says a GA (that is the number of weeks and days) and also the date (that is the calendar date) when it was done?  I assume you are saying that at that scan, she was told a due date because of what the scan said?  Is the estimated due date (EDD) also on the face of the report?
Blank
Avatar_f_tn
Hi Annie,

Am from India.  Am pregnant for 6W and 2days now.  My hubby and I are living away from each other due to professional reasons.  I have a boy friend and we had sex on the 29th Dec or so.  My hubby was here on vacation on the 3rd Jan till 8th Jan and I had sex with my hubby.  After he has gone, I again had sex with my BF during the week of the 12th Jan.  I now want to  know whose baby is this.  I have very irregular periods and really cant go with the exact date I ovulated.  I did a vaginal scan (because had a spot bleeding) on the 29th Jan and as per the scan it was 5W and 2D.  I read that have to sub 2 weeks from the scanning date.  That said, am getting convinced that this might be my hubby's kid but am very worried and scared.  Please help me on this.  I am really banking on your reply.
Blank
134578_tn?1404951303
Hi, Ashvi, you are correct about subtracting the two weeks and do sound like you had the lucky window, just late enough after the sex with your boyfriend that all of his sperm would have died, and just early enough to still be from your husband before you and your boyfriend had sex again.  But, what a mess.  Obviously you would not have a boyfriend if everything was perfect in your marriage, whether or not you are away from each other.  So what will you do?  Stay married and give up the boyfriend?  It might be a good thing to get some counseling.

Given how important this is, I would recommend getting a prenatal paternity test from Ravgen or the DDC with your boyfriend.  Your dates  are all so close together that it is going to be an anxious pregnancy otherwise.

Blank
Avatar_m_tn
Hello, i hope you can help me,, i was at the hospital on feb 3 , turns out I'm pregnant, but I've been spotting almos every month, im having problems with the pregnancy,  doctors did an ultrasound  2 different ones, and one said im 22 weeks, the other one said i was 26.1 and gave me a due date of june 9th, how accurate can this be?  They did some surgery to my cervix bc it was dilated, they had to make sure i was still a candidate for that, but my problem is i don't know when i got pregnant,  on August the 26th there was a break in where i worked and some things happened, really bad things and i though i was through that, but now i can't sleep just to think there's even a posibility  that i got pregnant on august the 26th, is this a posibility with my ultrasound putting my due date to be june 9th?  Please get back to me,  i don't want to lose this baby, but i need to know.
Blank
134578_tn?1404951303
At this point in your pregnancy, either 22 weeks or 26 weeks along, it will not be very accurate for dating the pregnancy.  On the other hand, if your due date is June 9, your estimated conception date is September 16, which sounds pretty far from August 26.  Did you have any ultrasounds earlier than this last one?
Blank
Avatar_m_tn
I posted the wrong dates, sadly i didn't have an ultrasound before this past tuesday, february 3rd in the emergency room the ultrasound cameback to 22 weeks, i was sent to maternity, i was told i needed a more accurate ultrasound  because the only thing they could do was , do a cartilage which closes the cervix but if you are over 22 weeks  you do not qualify for that, the next day on feb 4th they did a different ultrasound of the baby and the cervix, i was told i was 21.6 but my cervix was short at 1 but good news was that i did qualify for the cartilage,  but still dont know when my conception date was, due date if i was 22 weeks was june 9th but the new due date for the 21.6 weeks the didn't say, I'm worried of about getting pregnant on the 26th of august,  but i dont know how to feel about it anymore,  i just can't sleep thinking that might be the case .
Blank
134578_tn?1404951303
In your shoes, frankly, I don't think I would borrow trouble over this.  It sounds like you conceived in mid-September by all the information you have, any other information is not knowable at this point.  Probably what is going on that is causing you to lose sleep at this late point is that you have healed up just enough from the trauma of the break-in and are now beginning to process it.  (At first after a trauma, we are just in survival, and only when we begin to feel more emotionally strong can we even afford to think about it.)  If there is any financial support from the place where you work, see a counselor and talk it all over, and tell the counselor that you seem to be beginning to fixate on the rather unrealistic possibility that the dates of your pregnancy are wrong, and just talk over the whole situation.  It's pretty common, from what I see here, for a woman to transfer some life stress onto the fear that the baby's conception date is wrong.  Somehow that worry is easier to handle than the whole raft of worries about other, tougher things.

Good luck, I don't think you have a major likelihood that the dates are that far off.
Blank
Avatar_m_tn
Forgot to tell you, the other option given to me on feb 4th was to terminate the pregnancy of 21.6 weeks, the cartilage or don't do anything and wait. If there can be a 4 week difference in ultrasounds, that means i could've gotten pregnant on the 26th of august?
Blank
Avatar_m_tn
Thank you so much for your help, I've been worried sick about this, im not working there anymore, the neighborhood is bad and police is no increasing security,  plus im so embarrassed about the other girls seeing me naked, so i quit. But thank you i really needed Your help. Thank you.
Blank
134578_tn?1404951303
I don't think there can be a 4-week difference in ultrasounds.  Your first post you implied that one said 22 weeks and one that said 26, but you corrected it in your next post.  By "cartilage" I assume you mean cerclage?  It sounds like you can have that now, right?  They would not be doing one if you were too late to have the procedure.

Regarding quitting your job in shame, the bosses there owe you at least for your pain and suffering.  Get yourself to a torts/ personal injury attorney and tell what happened.  Don't neglect to mention that they did or didn't give you access to counseling, that you're pregnant now, and that you are going through stress with thinking it might be from that event.  (Whether or not it is, your pain and suffering over the issue are legally significant when trying to put together a claim for medical and therapy.)  If your former employer has any kind of insurance at all, it should pay for your coverage for some counseling help.  If you don't have the money to go to an attorney, call your nearest law school and ask if they have any legal clinics where you can get some help.  I would say that you have a really strong case that the employer should have gotten you both medical care and psychological counseling until you were well.
Blank
Avatar_m_tn
I've had sexual intercourse with a girl on 8/30/2014 and didn't inform me that she was pregnant until Mid December for whatever reason. But I'm most confident that the date given above is the date that her and I had this specific sex session. But here's the kicker...... She taken a ultrasound on the date 1/12/15 and it said that she was 22w2d into the pregnancy and the numbers don't appear to be adding up to me. her projected due date is 5/15/15. My question is, is she trying to pull a fast one on me or not???? because I've been doing a bit of online research about conception dates and its showing that she conceived wayyyyy before our acquaintance. Please help.

Thanks
Blank
134578_tn?1404951303
Hi, soldierguy, did she ever have an ultrasound scan in her pregnancy before January 12?  An ultrasound in one's 22nd week can have up to a two week margin for error when used to compute the date of conception.
Blank
Avatar_m_tn
To the best of my knowledge........she didn't. for whatever reason that was her first ultrasound session and it throws me off so much finding out this late in the game than anything. I'm asking for complete honesty and recommendations from you group members if possible.
Blank
134578_tn?1404951303
With the ultrasound being so late in the pregnancy, using it for dating (given the margin for error) she could have gotten pregnant pretty much from August 8 through the 5th of September. This does put you into the running, though you would possibly feel more sure if her date was about a week earlier, I assume?  Anyway, she might not have contacted you before because she thought the dad was someone else, and only just figured out recently that the dates (even with that wide range) don't make sense for anyone else.

Please keep in mind that when a doctor says someone is "22 weeks" pregnant, he means 20 weeks since conception.  The "weeks" count used by doctors begins on the first day of the woman's last period that she had before getting pregnant, not on the day of conception.

My suggestion, in order to feel a little more in control, is that you find out from the family court, in your local jurisdiction or hers, what labs they have certified to do DNA testing for paternity.  Then when you next are in touch with her, set up a date after the baby is born, possibly after the baby is a month or two old, to go to the lab and do your swab.  Having a concrete plan in place will help you stay calm while you wait for the baby to be born.  

I'm sorry this was a surprise, but in this day and age of available sex, a guy does sometimes have to take a DNA test.  It's the price one pays for what used to be called "getting some."  And for many guys (the ones the DNA test rules out), it's the only price.  Try to drum up a little compassion for the woman, she's not able to think that possibly the test will rule her out, and this means she is trying to work out the responsibility, logistics and the money for raising a child.  I assume it goes without saying that if this is your child, you will not be a scofflaw and a deadbeat.  You don't have to have a relationship with the mother, but you would have a moral obligation to a child of your own.
Blank
134578_tn?1404951303
excuse me, you might feel a little more certain that it was you if her due date was about a week later [not earlier] I assume?
Blank
Avatar_m_tn
I truly appreciate your time and acknowledgement. Your recommendations and logic thinking are words that i take at heart. Just wanted some sort of perspectives and better understanding since I didn't know how the whole conception system works. You're indeed knowledgeable within this area of specific and would be a tremendous asset to any other. Thank you so much and will most def remember this post.

Will keep in touch web-pal
Blank
134578_tn?1404951303
Please do keep in touch.  If there is any way to do so politely, you might suggest to her that any other possible candidates should also get tested.  But if that is not possible (to say this without giving offense), just be ready for you to get your DNA test with her and the baby.  Go to a certified lab, don't use a drugstore test.  She will probably want to see you do the swab (so you don't send your buddy in your place) and it is a good idea to have a neutral lab tech handling the swabs so no substitutions are suspected from her either.  But once it is done, it is done.  Call the family courts and find out who is certified for this kind of work.  (That is another reason not to use a drugstore test, I don't think they are certified, and if the test came up positive you would just have to test again for the courts.)

Good luck to you, and write back when you get the results.
Blank
Avatar_m_tn
my ultrasound states that im 9 weeks on feb 11 wen i went to the doctor. but my dd is sep 22 due to my last period is it posible i conceived when i had my period dec 16?
Blank
134578_tn?1404951303
Hi, you didn't conceive when you had your period, you conceived around December 30. (I assume your due date was given to you by an ultrasound?)  Doctors begin the "gestational age" count on the first day of your last period.  If you asked your doc, "Does that mean I conceived on December 16?" he or she would say no, you were having your period.  In the old days before ultrasounds, doctors needed a place to begin the count, and the only marker they had was the first day of bleeding the last time the woman had a period prior to pregnancy.  Women who are regular in their cycles generally ovulate about two weeks after that point.  So, if an ultrasound shows a woman is, for example, 7 weeks pregnant, that would mean 5 weeks since conception, and your doc telling you on a given day that you are 9 weeks pregnant is saying you got pregnant about 7 weeks ago.
Blank
Avatar_n_tn
Hi Annie

I really need your advise. Im 27 weeks pregnant. i went for an ultrasound and the doctor determined that my due date is 21 May 2015. I had sex on the 3 August 2014 with someone and a few days after that with my boyfriend. I'm not sure on dates. I had my period some time after that too. Not sure of dates either. I'm not sure who the dad could be. Please help
Blank
134578_tn?1404951303
Hi, 22cj, how early in the pregnancy was the ultrasound that gave you the due date?  It doesn't sound like you have a lot to worry about, but I'd like to know when the scan was that pinpointed your due date for the first time.
Blank
Avatar_m_tn
Hi Annie its 22cj. Sorry i forgot my log in details. I was 23 weeks pregnant when i had my ultrasound and thats when my doctor told me my due date will be 21 May 2015. I had my ultra sound done on 22 January 2015. Is my boyfriend the dad?
Blank
134578_tn?1404951303
It is too bad that you didn't have an ultrasound until so far into the pregnancy, since for purposes of dating, really only early ultrasounds are entirely reliable.  But it still does not sound like the guy you had sex with August 3 (and before you had your period as well) is the likely dad.  
Blank
Avatar_m_tn
Hi Anne I'm confused. Is the other guy or my bf the dad?
Blank
134578_tn?1404951303
It does not sound like the guy from August 3 is the likely dad, since you had a period after him.
Blank
Viewing 601-616 comments:
Post a Comment
To
Blank
Weight Tracker
Weight Tracker
Start Tracking Now
DNA / Paternity Community Resources
RSS Expert Activity
748543_tn?1371753642
Blank
TMJ/TMJ The Connection Between Teet...
Jan 27 by Hamidreza Nassery , DMD, FICOI, FAGDBlank
469720_tn?1388149949
Blank
Abdominal Aortic Aneurysm-treatable... Blank
Oct 04 by Lee Kirksey, MDBlank
242532_tn?1269553979
Blank
The 3 Essentials to Ending Emotiona...
Sep 18 by Roger Gould, M.D.Blank
Top Pregnancy Answerers
9523089_tn?1414215566
Blank
gueritacali
Chowchilla, CA
9704378_tn?1422324151
Blank
Miss_Courtney
Avatar_f_tn
Blank
Cheyenne__19
134578_tn?1404951303
Blank
AnnieBrooke
OR
Avatar_f_tn
Blank
lovebugwifey
10521833_tn?1413517124
Blank
Mouseee