pregnant need help determine the father

Okay so this is going to be kinda long I slept with guy A on october 29th took the day after pill on November 1st got my period on time time which was November 14th took pregnancy test was negative 10 days after pill and then slept with guy B on November 16 17 and still am to this day I got a positive pregnancy test December 6th and when I just got an ultrasound on 2-18 it stated that my crl was 14 weeks 4 days with an estimated due date of aug 15 2013? Please help me

[mommytobe612]

Please help me everyone

[AnnieBrooke]

Conception calculator says --

Probable date of ovulation:  November 22, 2012
Possible dates of conception:  November 18 to November 26, 2012
Due date:  August 15, 2013 (40 weeks)

It doesn't sound like Guy A is even in the ballpark.

[mommytobe612]

How can you be so sure ? This is my 1st pregnancy

[mommytobe612]

Very stressed & worked up everyday about this

[AnnieBrooke]

Are you thinking that because it  is your first pregnancy, an ultrasonographer would confuse a baby conceived in late October for one conceived in late November?  This being your first baby would not change the rate at which it develops compared to the average.

You ask how I can be so sure.  Because the ultrasound measured your actual baby.  The crown-to-rump length and other developmental measurements are a straight measurement of the baby -- the ultrasonographer looked at your baby, not a chart or a book.  The baby's size is then compared to the known information and data of many other embryos with known timelines.  

I'll give you an example.  I did IVF, and they know to the minute when sperm meets egg in IVF.  When I went for my first appointment at a different doctor, I had an ultrasound.  My IVF doc had told me that my baby's gestational age was 7 weeks 1 day.  Guess what the ultrasonographer said (who did not work in the same practice as the IVF doc.)  "I get 7 weeks 1 day."  It's not magic, it is data, based on measurements.

[mommytobe612]

So its not even something to worry about?  

[AnnieBrooke]

Guy A is not on the list of runner-ups.  If that is what you are worried about, take it off your mind.

[mommytobe612]

Thanks Annie sorry for being a hassle

[mommytobe612]

I just am extremely worried. And needed to know positively ya know