Good morning, I have a problem understanding my conception date...also this guy is starting to bother me at the last strech of my pregnancy becuase he thinks he's the father. Here's my story: I'm a regular 26 day cycle person and my last period started on the 15th of May. It was three days late and not heavy and didn't last very long. My boyfriend and I were constantly having sex except on the 19th which would have been my official last day if my flow would've been normal. On that day I had sex with someone else but I think he was trying to set me up because he wasn't sure if he did anything in me or not. So I went home washed myself inside and out. Then in June my period never came so I took a test and sure enough I was pregnant. Now they go by your last period but being that my period was late the last time how is that possible. So then I went family planning becasue I wasn't sure what I wanted to do yet and got an u/s. The doc said on the 29th of June that I was officially 6wks and 4days now I also heard the earlier for an u/s the better so that determined that I conceived before my 15th period. So after I got that news I decided to keep my baby...then I took my AFP test which came back abnormal and I referred to a specialist...that appointment was sometime in Sept and she determined that I was earlier than thought which was 16wks that day which was a Wednesday uhhhmmm I can't remember the exact date but it was sometime in the middle of Sept. So then I asked her the conception question which she already knew was coming after I asked my mother to leave the room. She said I conceived @ the beginning of May...so then I went back four weeks from then which then I was 20 weeks at that time and I asked her again and also requested an amnio to determine the father. She insisted that I didn't need that because the father was my then boyfriend and not the guy I had sex with on the 19th. So I was releaved until the guy popped up and is now emailing me saying that he thinks its his and calling me baby momma and things of that nature. I really don't care for this guy but I know he's going to be around until the baby is born trying to bother me!!!

Can you please help!!!