I had an ultrasound on Nov. 25, 2008 it said I was 6wks 5days pregnant. Is it possible that this pregnancy could be a result of having intercourse on Sept. 13, 2008 or would intercourse had to have taken place much later? How accurate is ultrasound dating? Help!

They are a guess based on the size which varies. So if you had sex with more than one person ( if that is the issue, just guessing) you really don't know till the baby is born and you get a DNA test

Dating the pregnancy by ultrasound is pretty reliable in the first trimester.

Try googling "due date calculator". You should be able to enter your estimated due date and see about when you would have conceived. There is always room for error as far as due dates and conception dates but it might give you a general idea.

I had sex with guy 1 on Sept. 13th, 2008. The condom came of in me during sex but he quickly realized it and stopped. I believe I started my period on Sept. 28th. On Oct. 4th I had sex with guy 2. We did not use a condom and he did not pull out. I had sex with guy 2 again on Oct. 11th. On Oct. 30th I found out I was pregnant and then I had an ultrasound on Nov. 25th that said I was 6wks 5days pregnant. So I guess my question is could guy 1 have anything to do with this pregnancy? I believe that was my period because I bled for a week but I hear that some women experience implantation bleeding. (this is just to give more info on the previous question)

Was the period around the usual time it would be expected? My guess would be the baby is guy number 2's. The scan will give you a closer date, although not necessarily exact, than using your last period date. As Fr_Chuck said, a paternity test is going to give you an accurate answer. Hope it turns out like you would like it to.

Yeah my periods have been pretty regular and usually come around that time. Thanks!