preggo or nah?

okay so about 3 days ago my bf and i had sex for the first time but it was unprotected( i know i'm dumb ass) but it barely last like 15 seconds. after he pulled out i felt his dick and there he was coming but it was pre cum. can you get pregnant from pre cum?? it was also my last day of my period, but it ended that morning. i think we were just paranoid cuz it was our first time but i got a plan b just in case. do you guys think i'm okay as in not pregnant?