cd 14 brown spotting

hello everyone i got my period exactly 14 days back. today i noticed a lot of but still spotting like dark brown blood in my underwear. i’ve been a little sick since 2-3 days so i’ve taken medicines too however i met my boyfriend three days before my period and we had oral sex but his tip (might have pre cum idk) touched just my vagina for 4-5 seconds. i can’t be pregnant though right? since i just had my period? i’m sorry i know it’s a stupid question but i just need some reassurance :(