HELP PLEASE!!

I’ve been looking all over google and books and shit and I don’t know the answer. I got my period at the beginning of this month and my boyfriend and I had unprotected sex twice after my period was gone and then today I got a cramp that was the worst one I’ve ever had and I think it was my period but it was just like a splurge of blood and then now it’s just barely here so I don’t know what the answer is. I am on birth control too so i’m nervous