please i’m only 17 i’m so worriedl

okay so when me and my boyfriend had sex saturday he pulled out and cummed on the floor , but i am on the pill but yesterday i stopped for some days because of the side affects so my mother is getting a new brand today so now today i have slight cramps and brown discharge as if my period is about to start am i pregnant or is it because i haven’t took the pills ? once before like 3 months back i left my pills at home while i was on vacation and hadn’t taken them in a while and the same spotting and cramps happened but at that time i was a virgin so i wasn’t worried , is this the same thing?