Brown sporting. HELP!

Anastasia

I just recently lost virginity. Before that my periods would come around these days 24-27, but after they moved to 1-5 (begging of month) so these last 2 months I got them around that time (1-5) But on 24 (usually the day i got my periods before i lost my virginity)i got brown spotting. My last sexual relationship was on 10 of August, right after my periods ended( everything was protected. We are using condoms+pull out and after I always check if there is any holes in a condom and there wasn’t any) My breast don’t hurt, they didn’t change the size, my stomach doesn’t hurt, nothing unusual at all! What can it be ?! I checked internet and everyone is saying that it’s pregnancy. Can it be due to the stress? I just moved ! And changing school rn...