pregnant & Confused

I had sex with an x we have never used protection and I never did end up pregnant in this occasion he as well pulled out ....i am back with the father of my child around the same time my bf and I had sex on 2 different occasions and he came in me now im pregnant im more than sure my baby is my bfs but still have doubts I am sooo scared.I just wana know and hate it because I did not keep track of the dates and last menstrual period was Nov 19 I know one occasion of my bf was before thanksgiving and other around Dec 3-5