Dating Scan

[Misslady259]

My LMp started nov 29, 2012 I had sex with my bf from nov 30-17th I had sex with an ex dec 18th we started off with a condom and he drinks really heavily but he finished without a condom got a positive pregnancy test dec 28th was told on March 21 2013 that baby was measuring 15wks 3days how accurate can that be being your scan can be really off in the 2nd trimester and who's more like to be the father with these given dates when did I most likely ovulate and or conceived. Just need a little help please!

[AnnieBrooke]

I'd guess it's your boyfriend's baby and not the drinking guy's baby, but as you probably know, there is no way to be certain by now.  The time for a dating ultrasound is eight or nine weeks past. The fact that your proposed conception date would be around the 13th if you had perfect, regular periods with perfect ovulation right in the middle, and that you got a positive pregnancy test only ten days after the sex in question, both suggest but do not guarantee your boyfriend is the dad.  I'm sorry; there is nothing you can do to be more sure besides get a DNA test.    

[Misslady259]

Well technically yes it's the first one I had another one at the ER jan 1,2013 and they couldn't seem anything but a sac said I was really early but that's the first reAl one I had... Got a edd of sept 5 but that's just doc going by my LMP he really sucked I just switched doctors and last week was the first time I even got to hear baby's heartbeat haven't had a US with new doc yet!

[AnnieBrooke]

Was the 15th-week ultrasound the first one you had, and what estimated due date did they give you?