Help! Pregnant?

May

My boyfriend is almsot 17 next week.And im 16 next month.To be honest,i don’t need the comments about how I’m stupid and that I need to be more responsible and I shouldn’t be having sex at a young age.But genuinely I already know that.I’ve learned from tonight and have decided I’m going to do better.I’m setting rules for myself and not allowing any of this to happen again.I need help tho.What is the chances of getting pregnant from precum during ovulating.Is the chances high and how do I prevent getting pregnant from this.My boyfriend says he doesn’t know when he is gonna precum and it just happens and he can’t feel it so he doesnt realize it sometimes.Today we had sex 4 times without a condom and one time with.The last time we did he pulled out and i put my lips on his tip and he finished immediately.I asked if he precum in me and he said he d didn’t but that concerns me because the other day he precum in a condom and didn’t realize it.I am terrified he did and I’ll get pregnant from precum.What do I do.He’s gonna try to get me a plan b tmr but he doesn’t know if he can.I need help asap on the percent levels.I’m ovulating rn which makes matters worse.I already set rules between us and told him this won’t happen again and he was very understanding.