I need advice

So I’m 22 and in a pretty serious relationship. Im terrified to have sex with my boyfriend because I don’t want to get pregnant. I love everything about and how close we are together in those moments. But every time afterwards I always think anything wrong with me is because I’m pregnant. I’m on birth control and he always wears a condom but I know that even then there is still a risk of pregnancy. He doesn’t understand why I’m as scared as I am since we are taking so many precautions. I figure with time I will realize that I haven’t gotten pregnant yet so what we are doing is working...but how long is that? I make myself miserable for weeks at a time thinking about it and waiting to see if I’m pregnant or not. I’ve gotten in such a bad habit of going and buying pregnancy tests now that first response is paying their payroll from me lol. I have friends that have gotten pregnant and I see how hard it is on them right now and I don’t want that, and abortion or adoption could never be an option for me.

How do you get over thinking your going to get pregnant and trusting that the birth control is doing what it should?