Sex on period

So I got my period last Friday and it was so heavy, yesterday I had sex while still on my period though I didn't bleed at all and it was really light to where there was barely any blood but before doing it I was bleeding and he did cum inside me, I'm just abit confused my period usually lasts 5 days and has never done this before, can sex do anything to stop my period or am I just experiencing my period finishing early? Although when I go toilet and wipe there's still a little bit of blood that comes out