Any Help, i don't know what to do or how to feel😞

So i lost my virginity about a week ago and i had sex with my bf this saturday. And he had a protection and i am sure everything is fine with it but now my stomach won't stop with the pain and my period is late 2 days and that is quite odd because my period was always on time since i first got it till now. And yeah i'm 16 idk id that is something that maters i just need someone to calm me down and tell me i'm not pregnant. please