Bleeding

I was with a guy yesterday and when he was fingering me (kinda roughly) I started bleeding a lot. My period ended 4 days ago and since I’m on the pill it always end that same day with no bleeding afterwards. He ended stopping fingering but a little bit later we had sex because I wasn’t bleeding anyone more. When I got home there was some spotting in my underwear and again this morning when I went to the bathroom there was a fair amount when I wiped. Wtf could be causing this bleeding?