Who is the father of my baby?

[Thatonegirl00]

I had sex with my ex December 9th, I had my last period December 22nd. But I slept with my current boyfriend the beginning of January. I am now 30 weeks and 4 days. Who could be the father ?

[AnnieBrooke]

Hi, it would be helpful to know how early in your pregnancy you had your first ultrasound, and whether the due date of the baby was given to you from measurements in that ultrasound or from the doctor using the first day of your last period and a little cardboard wheel to compute it.

[Thatonegirl00]

I got my first ultrasound at 16 weeks. The due date was from measurements and she decided when my lmp was from that because I never really kept track of it. I'm due September 28th. If I count back from how far along I am, it goes back to the 22nd which is about 2 weeks after I had sex with my ex, but if I look it up I conceived January 5th ?

[AnnieBrooke]

OK, well, though a 16th-week ultrasound can be off by +/-  a week or 10 days for purposes of trying to guess a conception date, it still doesn't point to sex on December 9 causing the pregnancy. If you got pregnant around the 9th of December, your baby would have been much further along in its development, and your due date would have been at the end of August. Is the reason you are concerned that since you can't remember when your period was for sure, you think maybe you didn't have one? You would still never have gotten a due date of September 28. That is weeks too late for the sex on December 9 to have produced the pregnancy.