who is more likely to be the daddy?

[babyJ2062]

my LMP was dec.1st  so by using an ov calculator and prego calc. it says my conception day wouldve been dec 15th.. i had sex with guy a on dec 9th and then with guy b on the 13th 14th and 15th.. who is more likely to have fathered my baby?? a or b?? thanks for the input

[babyJ2062]

Ok so I went for an early ultrasound yesterday and the baby measured 5weeks 5days.. so based on that who would more likely be the father ??a or b? The conception date would've been dec. 15th

[AnnieBrooke]

If the ultrasound was yesterday, I get December 14 for conception, not December 15.  Too bad.  Both guys are still firmly in the running as of December 14, since sperm can live 5-6 days in a woman's reproductive tract and you had sex on the 9th.  But as you can see from the dates, the guy from the 9th has quite a bit of a a lesser chance than the guy from the 13 and 14th.  It's just that the dates alone don't rule out the first guy entirely.  

[AnnieBrooke]

Until you get an early ultrasound that tells you an estimated due date, you have to assume that either guy could be the dad.  

Some women don't ovulate on the schedule provided by an ovulation calendar and pregnancy calculator. (All an ovulation calculator tells is when an average woman might have ovulated.)

Best thing to do is get an ultrasound around January 15-20, and tell the doctor you don't know when your last period began, and ask for an estimated due date based only on the embryo's measurements and developmental markers.  Then take that due date home and plug it into a conception calculator online or just count back 266 days, and that will give you an estimated conception date.  I just hope the date it gives isn't the 13th or 14th, since both guys' sperm could have been alive in your system at the same time on those days.

If the ultrasound does point to a day when both guys could be the dad, there are prenatal DNA testing companies out there that (for a big fee) can do a blood draw from the mom's arm and swabs for the possible dad(s), and confirm paternity before the baby is born. If you do go that route, Ravgen and the DDC are reliable labs. Most women prefer to save the money and test after the baby comes for only a tenth or so of the cost.

[AnnieBrooke]

I guess I should have asked, do you know that you are pregnant?  If so, the above advice applies.  If you were just asking in case you had gotten pregnant from the events last month, my advice would be to wait until you know for sure that you are pregnant before speculating on which guy would be the dad, it's so tiring to do.