I was with an ex February 10th and 13th only not sure in he ejaculated inside of me or not we used condoms but not when we started. I missed my period in February which was expected around the 21st-24th and it came on March 9th 20112. I found out i was pregnant around May and had my first u/s when i was 15 wks 4 days pregnant going by lmp, well the u/s put at 16 wks 2 days measuring 5 days ahead. In my fetal scan i measured 5 days ahead also. My question is it possible my ex is the father? I took a test after i was last with my ex around March 3rd and it was negative then on the 9th had that light period. My cycles are sometimes irregular and sometimes i do skip a month. I'm concerned that light period could've been implantation bleeding and my ex is the father. I did pass clots which i hear you won't see during implantation bleeding and it wasn't spotting but light. I was only with him those two days and was only with my current boyfriend in March. My due date is 12/14/12 and 12/9/12 by u/s they match to be my current boyfriend's but i'm worried because i'm measuring ahead and that i could more than 5 days and the u/s is just saying i'm only a few days ahead. Advice would be greatly appreciated i'm confused