Sexual assault.... pregnant?

I was sexually assaulted on the 6th, at a party in my first night of college. I’m pretty sure the dude finished inside me. I have had a 28 day cycle ever since I got off of birth control. I have a boyfriend, and i had sex with him during my fertile week (25-1). I didn’t track ovulation this cycle, but i do have a 14 day leutal phase. I just found out I’m pregnant , and I just want to make sure it’s not this assholes baby. My boyfriend and my school knows, but my boyfriend doesn’t want me to have it if it’s my accusers (neither do i, he really ruined every part of my life) i was just wondering, since my cycles are always 28 days, would i ovulate on day 14 of my cycle? Any comments are appreciated.