My boyfriend had sex with a woman june 9th, she also had sex with a man june 16, she is due march 12, 2013. she had asonogram july 19 that dated her 6 weeks, 3 days. she had a period june 4th to 8th.?

Very confusing: Sounds like a paternity dna test may be necessary. Sperm can live up to 4-5 days in the body, contrary to anything else you may have heard or read. So its possible that any of them could be the father. As to the "period" if she is pregnant this could be a sign of miscarriage and she should seek obstetrical help asap!

No good answer: If you're trying to figure out if your boyfriend is the father of the child this woman is pregnant with, pls remember that either way, he's still having sex with someone other than the person who's supposed to be his girlfriend (you!) they won't be able to determine who the father is by dates, & the real question is why does it matter to you-either way he's sleeping with someone else. Sorry...