Not sure what's happening...help?

Alright so I slept with a dude on Friday morning, we didn't use a condom, he did pull out well before he came. So all is well. I've been feeling slightly nauseous since, but I feel like if I really was pregnant that's way to early to tell. Well tonight we had sex again, without a condom, same as before. When I get home I go pee and there is blood, my period finished like a week and a half ago, is it just because he went kinda hard? Or uhh like would it be spotting? Idk...