Aa
A
A
Close
Avatar universal
paternity scare
Hello, I would like to know exactly how acurate an ultrasound is that is saying I am 7 weeks exactly. I have been with my husband for over a decade and just found out im pegnant. only probably is back in may I had a one night encounter with the father of my 13 year old. soo, on may 15t i got my period and it was on date expected, i ten had sex on the 22nd of may and took a plan b pill may 24th. I then got my period again on may 31st I believe and it was either really early or not a real period. the guy I had sex with non may 22nd said he did not ejaculate inside me but i chose to get a plan b just in case. nI have a due date of march 11 from ultrasound and due date of mar 5 from the may 31st period. I just worry that I got pregnant in may and my ultrasoundm is 2 and a half to 3 weeks off. my husband woulld be devastated please help
Cancel
17 Answers
Page 1 of 1
7818018 tn?1406158041
Some doctors say they're accurate. Especially if you get them done early. I have a friend who had sex with 2 guys almost a month apart and she had several of ultrasounds done even the transvaginal and they all came up as the same cute date which means she got pregnant with guy B but when she got the DNA test done guy A was the father so the ultrasound dates were way off. My advice to you is get a DNA test done if your worried and to be safe. Good luck!!
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
7818018 tn?1406158041
Due*
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
134578 tn?1483549754
Hi, Pattyann, I hope your friend got a second DNA test done, some of the inexpensive labs are notorious for errors.

Jazi, for a March 11 due date, the estimated day of conception is June 18, with June 16 through 21 the suggested margin for error when the ultrasound is in the 7th week.  It does not sound like Mr. May 22 had anything to do with anything, especially given that you had bleeding beginning May 31.  If you had gotten pregnant May 22, the doctor would not have told you that you are at 7 weeks.  If you are entirely freaked out, you can test at the DDC or Ravgen labs, a prenatal DNA test is quite costly but can keep a woman from being stressed her whole pregnancy or making a tragic mistake.
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
7818018 tn?1406158041
DNA test was correct guy A was puerto rican nd guy B was white her son came out looking actually like guy A. I think she might of been mistaking of who she slept with on what dates but she swears she remembers one on her birthday and the other on vacation. Or the place she went to had no idea what they were doing. Idk but I was a Lil surprised
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
134578 tn?1483549754
I've just never heard of an ultrasound mistaking a baby when the dates are a month apart.  Babies on ultrasounds look so different when there are weeks in between!!!  It's more likely that there is a mistake in her memory than that an ultrasound seeing, for example, an 18th-week pregnancy would confuse it for a 14th-week pregnancy.
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
7818018 tn?1406158041
That's exactly what I said. But she refuses to be wrong and swears she remembers. Now I've heard of ultrasounds being off maybe a week or so but not that long.
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
134578 tn?1483549754
Well, as long as she has had a reliable DNA test done at a lab certified by the family courts for determining paternity, that is what matters.  Sometimes when the answer is a BIG surprise, I recommend a second test.  But always at a certified lab, not a drugstore test.
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
Avatar universal
thank you very much, i only got concerned due to the 2 periods in one month and people saying ultrasounds are not qccurate it would have to be almost 3 weeks off if it was may 22nd sex. and i just dont see an ultrasound being that far off but ii still worry daily. july23rd was my ultrasound so i would be about 9weeks 4days today. i am so worried and need to stop listening to everyone telling me i still should worry
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
Avatar universal
i also know in my ultrasound pic the yolk sac was still about the size of the fetus and at 3 weeks further along or even 2 this definately would not be the case..i got an ultrasound friday and it seems the placenta has fully taken over so what time of pregnancy does that usuall occur?
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
134578 tn?1483549754
Jazi, trying to double-check the ultrasound tech on every developmental detail is the road to craziness. If you don't understand or believe the ultrasound, talk to the doctor. But regarding the competence of the ultrasound tech and the doctor, three weeks is a huge gap and they just aren't going to get it that wrong.  The more you talk to "everyone" who tells you that you "still should worry," the likelier it is that your husband will get wind that something happened.  If you don't intend to tell him and if you never intend to cheat again, this will put you in a bigger bind than it is worth.  Instead of scaring yourself with dates that show no reason to be scared, make it your goal to figure out what happened in your marriage that caused you to cheat, and what you are going to do about that to make things great for your husband, your child and you together as a family from now on out.
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
Avatar universal
Thank you for everything. I will let this go now. have a happy pregnancy and marriage
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
Avatar universal
Ultrasound dating of conception is not reliable for determining paternity because the ultrasound can be off by at least 5-7days in early pregnancy.
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
134578 tn?1483549754
Hi, firsttimemommy, the ultrasound will not be off by 5-7 days early in the pregnancy.  It can be off by 5-7 days by the end of the first trimester, however.
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
Avatar universal
Hello,
I hope you can ease my mind a little bit. My lmp was 4/27-5/1 and they have been irregular for years ( always 30+ days apart) had sex with guy X on 5/1 then boyfriend 5/4-5/30 every few days. Got a positive test on 6/12. Had an ultrasound on 6/23 and the transvaginal u/s said I was 5w4d with twins.... Giving me an edd of 2/17. Then went to another clinic for u/s on 8/12 which said I was 13w4 days....and edd 2/5. After calculationg conception dates I'm getting 5/15 based on the earlier due date as I'm just trying to rule out guy X.  I think the early scan I got shows that I may have ovlated really late( hence my lengthy cycles) but wat are the odds that guy x could be the father from the one night stand on 5/1?
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
134578 tn?1483549754
You had an ultrasound on June 23 and they said you were 5w4d pregnant?  It doesn't sound like the guy from the 1st of May has anything to do with it.  Going by your first ultrasound, you would have conceived around May 29, and going by the second one you would have conceived around May 23.  (Possibly you don't know -- when they tell you that you are 5 weeks "pregnant," they are not telling you when they think you conceived, but when a person with a standard cycle would have had the first day of their last period.)
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
Avatar universal
Hello Annie, yesterday I had another dating ultrasound due to my worries and I was told that I am 11 wks and a few days putting my due date at march 6 or 7 the tech said. the due date I got based off lmp was march 5th and first ultrasound dd was march 11th... so, it seems they are all right within a week from eachother. which I was relieved because that means I conceived in june sometime correct? so my only remaining question would be that I recently read sperm can live inside you for 7 days. so if i had sex late may 22nd which really makes it the 23rd of may, is there any way that I could have gotten pregnant by that intercourse? i only ask due to the estimated date of conception being so back and forth. I was told at one point I could have gotten pregnant june 1st or around there which I was on my menstrual then but I just want to be 100% sure that may23rd sex could not have fertilized an egg and me be carrying a child from an ex. when I calculated it I would have had to of conceived after the first week of june like june 7th and after. I just was not aware sperm lived in you that long and that has me worried now. if my duedateislets say march 5th the earliest gave to me what would be the biggest possible window or time frame for conception dates?
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Comment
Post Comment
134578 tn?1483549754
Hi, jazi, even if you got word from someone who could magically tell who the baby is from, you would still be anxious and saying "but I just want to be 100% sure."  Read the dating analysis above.  The early ultrasound is the most accurate for dating. That all said, I assume you will probably want to do a DNA test once the baby is born because the baby's arrival is evidently not going to stop you asking and wondering.
Comment
Cancel
Comment
Avatar universal
Could you help me Annie? You seem very knowledgeable... Im not sure of my LMP. but I got an EDD of Dec 8th 17... that means that my LMP was roughly March 3. Ovulation was around 11-17 of March. I was having sex with my boyfriend all March. And on April 1st I had sex with and ex boyfriend. Could my ex be the father of my child even tho my conception date is 15 days apart
Comment
Cancel
134578 tn?1483549754
Hi, LPMommy, could you post this as its own question? You've added it to a thread that is 3 years old, and your question is hard to find. Go to the top of the screen and there will be a red button to post your question. Just copy and block what you wrote here, and make it its own question, and it will come to the top of the list.
Comment
Cancel
Avatar universal
Comment
Comment
Comment
Post Comment
Your Answer
Avatar universal
Answer
Do you know how to answer? Tap here to leave your answer...
Answer
Answer
Post Answer
A
A
DNA / Paternity Community Resources