im 20w 1d pregnant. i had unprotected sex with my now ex-boyfriend for almost 2 years and never got pregnant. i also have irregular periods. so me and him messed around up until november. by the end of that month we didnt have sex and i was already talking to another guy since my ex had a girl. i ended up having unprotected sex with my new bf about the second week of december it actually happened twice that weekend which was the 12 and 13. i didnt get my period in november but i thought nothing of it because it always happens anyway. come to find out late january i was pregnant. i had taken a pregnancy test the third week of december and it was negative but when i had my first ultrasound on feb 23 i was 11 weeks pregnant. my due date is sept 14. my confusion is that according to my due date i got pregnant about the 7th or 8th of december. but i hadn't been with either at that time. since the conception date is only days off from when i had sex with my bf, could it be that the ultrasound is just a little off and my babys father is my bf and not my ex??? i am so confused since my LMP was beginning of november probably even october and i had an ultrasound early which is more accurate of the gestational age so i cant figure it out!! i need somones opinion PLEASE!!!