Just a little worried

Okay so I definitely went out of my normal zone and I had a one night stand with someone. We had sex for nearly 2 hours and it was protected and I was on my period, but it was really rough. He pulled out and everything before coming but I think it's just a mixture of paranoia and surprise that I actually did that that's making me worried. Could anyone give me advice to calm down and does anyone think that I could've gotten pregnant?