ugh my bf wont believe me

Eve

so we had unprotected sex today and we are still in highschool. yeah i know stupid to do. but we have never had sex with anyone else besides each other.

anyways he thinks I might me pregnant. my period is supposed to start tomorrow so my window is closed.

sadly he doesn't believe me, hes really scared about it.

what should I tell him?

please no hurtful comments