Pulling out vs Condom

I don't know if my boyfriend pulls out or uses a condom but I feel he does both, whicheever he feels that day. About 2 months ago my sister had sex with a condom for the first time in a long time, it broke and she had to use plan B. I know a condom is ideal but it's clearly not as effective either. All this stories about pulling out are scaring me 😳