Bleeding during sex?

Not a virgin, but I've been experiencing bleeding during or after sex several times and I can't figure out why.

I have a guess that it may be my period coming early either due to stress, starting a new birth control pack to avoid getting my period and my cycle trying to get back to normal, or taking the pill 2-3 hours after my usual time (but still on the same day).

I also wonder if it has to do with the fact my boyfriend is fairly large and maybe friction may have something to do with it, but my last boyfriend was also well-endowed and I never experienced bleeding like this that wasn't period-related....although my current boyfriend hits the cervix more during sex so maybe he does have something to do with it??

I'm lost 😕