my period was 3 days shorter than usual bc it’s usually 6 days but it was only 3 days this month. the day before i spotted brown/red blood. it was lighter too because i didn’t bleed at night like i usually do but i did have it heavy enough to fill up tampons with blood clots. the blood was red. i started birth control on march 10th so i’m starting my 3rd pack tomorrow. is this bc of my birth control pill??? is this normal? this isn’t a sign of pregnancy right???? help???

btw: i haven’t had sex either but his penis was rubbing against my vagina for a few minutes so idk if he precam and this was on april 10th