I'm supposed to have my period today but my boyfriend and I had intercourse. Help?

This is my first time in Patient and forums in general. I wanted to ask about whether I am pregnant or just late. My last cycle's first day was Feb 19. At March 12, my boyfriend and I used the pull-out method like we always do for the past 2 years.. But when we do that, he wants me to swallow instead which was fine. We had intercourse and did oral after, but what worried me was when he inserted his peen in my mouth already, I noticed that it tasted like semen right away even before he "finished" or felt the orgasm as is. I'm not sure if it meant that he already came inside or if that was precum, because when that sort of situation happens, he's really unaware about when and why the semen comes first before the orgasm. Since I've been expecting my next cycle, it might be possible for me to hear that I'm only either extending a few days or if I'm actually pregnant already. I also would want to know more about when ovulation starts. I wanna know beforehand about what else I can do to avoid having the baby to form? Thank you so much! I'm sorry for the long statement, I just wanted to make sure I cleared up my situation to get the most trusted answer I could get 😦