I need opinions

Okay so Ik this is mad dumb to say but what if you and your partner were foreplaying and he nuts and it gets on your vagina but not sure if it got in the hole it got more at the top (my skin) and lately i been stressing . Me and him haven’t had sex yet but I been stressing also I was supposed to start my period yesterday and all I got yesterday was red and today it’s brown idk why tho