Should I let my boyfriend cum inside of me?

I’ve been on birth control for about 7 months now. I take it everyday, around the same time. He has done it before by accident, but it was always just a little bit. I always took a plan b when he did it, which I know is not the right thing to do, but I just get super nervous. He really wants to experience it and I’m not going to lie, I kind of do too. I guess my main concern is bc failure. What was the first experience like for you if you’ve ever done it? I’m just super nervous I guess.