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Well in the month of July my current boyfriend and I were not together. I slept with somone once, we used a condom and pulled out... i wish i never did this. The was during the last week of July (I don't know the exact date). Then On August 10, my boyfriend and I got back together and we slept together on that day and everyday after that. I took a pregnancy test about August 25 and it was negative, then i started getting sick and took another in October and it was positive. One october 19 I had my first ultrasound saying i was 10 weeks and 3 days, therefore making my conceive date around August 21 and my due date around May 13, 2008. My periods will come one month then i will not have another for 2. How accurate are ulstrasounds? And what are the chances that the baby is not my boyfriends? I'm really scared and regret ever sleeping with the other guy. PLEASE HELP!