Don't want children

My boyfriend and I been together for 4 years faithfully, he is 21 and I'm 22. We lost our virginity to each other when I was 20, which didn't last long because of my fear of getting pregnant during unprotected sex. We both don't want children (as so he said)but constantly have this debated about having unprotected sex. He wants to do it with out protection as I want to do it with protection, he said to trust him and that his pull out game is strong but how can that be determined if we barely have sex? I don't trust it, the same thing happened with my mother, plus she was on birth control, I'm not. Idk what to do