Help pls

So I’m under 18, and me and my boyfriend of 7 months (I’ve known him for five years) tried to have sex. His penis wouldn’t actually fit in me, and he had a condom on. Idk what happened, maybe he just didn’t put it on correct or it was too small, but after a few tried, it had broke then I got off. He didn’t actually cum, but there was probably pre cum somewhere. He says since it brok when I got off it’s fine, and I’m on birth control for bad periods but I don’t take it regularly at the same exact time everyday and I take it kinda weirdly since it’s hard to swallow for me. All my friends keep telling me to get a pregnancy test. This was 3 days ago. I know there is a chance to get pregnant from precum and even if your on birth control. My mom doesn’t know I’m sexually active either.