Blood from sex? Or my period?

Li

I’m not supposed to get my period til Thursday and my bf and I had sex yesterday. All of a sudden like a fountain of blood came pouring out and I’ve been having some cramps but not really my normal ones. So I put a pad in thinking it was my period and now it’s gone.. my other thought was it could have been from sex cause it was hurting during, but I’ve never had so much blood from sex 😕 thoughts? Advice?