Ultrasound Accuracy

[babyboom180]

The first day of my last period was Aug. 10 2010. I was with a man on Aug. 19 2010 but there was only penetration for about 5 minutes and he didn't ejaculate. I got back together with my boyfriend on Aug. 25 2010 and we had intercourse and he ejaculated 3 times inside of me. I had 3 early ultrasounds all about a week apart. The first one set my Date of Conception as Aug. 27 2010. The next ultrasound one week later set my Date of Conception as Aug. 29 2010. and the third one almost two weeks later set my Date of Conception as Aug. 25 2010. All of these days were days I was together with my boyfriend. My due date has been consistently 05/18/11 with my OBG which would set conception as the third ultrasound and according to my calculations when I should have been ovulating. Through my whole pregnancy I have been sure that the baby was my boyfriends because the other guy didn't ejaculate and I had only been off my period for a few days. Plus the fact that the 19th of Aug. never came up in any of the predictions of conception date. Can someone put my mind at rest please?

[Melissa_1982]

I have to agree with JoyRenee.  Because you were with both of them so close together it's too hard to tell who daddy would be.  

[JoyRenee]

Unfortunately pre-ejaculate does contain some sperm and pre-ejaculate cannot be felt by either of you. Also sperm can live up to a week in the vagina. All dates are also estimates. Implantation occurs 7-12 days past ovulation which can give you dates that are a week off even if you conceived with the first guy.

I have to go with DNA test for this one.