Gestational Question

[fuzedguy]

If a female is 7w3d pregnant (found out by U/S) and the last time we were together was 8w2d ago, is there any possible/conceivable chance that it could be mine?

 

[Fifi61467]

Hi there. Yes there is cos you are actually counted as 2 weeks pregnant when you conceive. When you miss a period you are only two weeks from having done the deed but 4 weeks pregnant. Also sperm live quite a few days and womens cycles are nit spot on. I know exactly when I 'got' pregnant. But they put me back a week on scan.
Hope this is the answer you want

 

[fuzedguy]

Even though the US had her a week later getting her period? So I was 3 weeks away from possibly bring the dad...

 

[Oneday]

Hi
Sorry I would say no. She conceived 5 weeks 2 days ago from the scan, sperm can live up to a week so you would have needed to have done the deed at the latest 6 weeks 2 days ago. However nature is a funny thing and could prove this to be wrong. Have you asked her if she slept with some else ?

 

[fuzedguy]

She was with me once an I used the withdrawal method, she started seeing someone at most a week after me.

 

[Tanikit]

The maths involved:

Sperm can live up to 5 days in a womens reproductive tract (can even be 7 days though this is unusual)

Which means if you had sex with her 8 weeks 2 days ago then she fell pregnant somewhere between 8 weeks and 2 days ago and 7 weeks and 4 days ago

Ultrasounds are not that accurate at determing how far pregnant a woman is. An early ultrasound can be 5-6 days inaccurate either way which would make your gf anything between 6 weeks and 4 days pregnant and 8 weeks 2 days pregnant when the scan was done

You need to find out how they are aging the pregnancy also as usually a pregnancy on a scan will add two weeks to when the women fell pregnant, which would mean she fell pregnant somewhere between 4 weeks and 4 days ago and 6 weeks and 2 days ago at which time you were not around and therefore the baby should not be yours.

However things have gone differently and the only way to know for sure is to have a DNA test after the baby is born or if your gf has an amnio you could ask for it to be done too. If you really withdrew correctly you should also not have been able to father this child.

 

[fuzedguy]

Sh was dated by ultrasound. 7w3d is date of LMP (estimate) and from what I remember she wasn't on her period when I was with her. So it would have been sometime after.

 

[fuzedguy]

The only placE I've heard first trimester ultrasounds Are inaccurate have been message boards. All documented sites date have said first trimester ultrasounds are really accurate like +-3 days. And as far as sperm life, the average ive seen is 2-3 days. Rare does it ever stay alive passed 4 days.

 

[Fifi61467]

To be honest ( and I don't mean to be rude) the only way for you to be sure will be a DNA paternity test when the baby is born. You will get so many answers here and there is only one sure way to guarantee the result. Everything else is hypothetical. And sometimes the improbable happens.

 

[knitbit]

If you had sex at 8w2d, but sperm hung out 1w before she ovulated, then she could be ~9w2d pregnant. Given that she is only almost 2 weeks off from that, it seems unlikely you are the guy. I agree that you should insist on a paternity test if you do not believe the baby to be yours.