Could I have had a miscarriage?

I had unprotected sex on 12/1 and we did it for so long and I don’t even know if he came or not. I was supposed to get my period on 12/13 and it is always on time every single month. But on Sunday 12/9 I woke up and went to get a shower and blood and blood clots just ran down my leg it was like a water fall. I put a super plus tampon in and bled through it within less than 2 hours which my period is never this bad. I have such bad cramps. The bleeding stopped for a little last night but now is back to bleeding pretty bad. Could I have had a miscarriage or is it just my period being extremely bad?