Who could be the father of my baby?

I had sex with my boyfriend on the night of dec 11th and noon time on dec 12th with no condom... I had sex with my ex with a condom on dec 14th... and it last for about 7mins... so right when he was climaxing I pulled his penis out by the base slowly and when I looked at it there was no air and very little clear semen in the condom... there were no obvious tares or rips so I know that it didnt bust... but I was moist afterwards... but im usually like that around the time I ovulate... so anyways I had unprotected sex again with my boyfriend on the 17th of dec... my last period was november 30th and my cycle is 30 days... so now Im currently prego and my due date is sept.7th so what Im basically asking is could my ex be the father of my baby???