Bleeding after sex

I had sex with my s.o 2 days after my period had ended (keep in mind we hadn't done anything for a while) everything was going good, but mid way, I started to bleed (heavily). We immediately stopped everything. I wasn't in any kind of pain or anything, I was just bleeding. I bleed for about two days. And now I'm not bleeding anymore but I have discharge, that of when your uterus lining sheds...has this happened to anyone before? Should I be worried? Any thoughts of what might've caused this? Thanks in advance 🙂