Anxiety over Sex??

Okay I really need some advice. I have been with current boyfriend now for 3 years. In the beginning I didn’t have this problem. But for two years now I have had severe anxiety about becoming pregnant. We always used condoms, I even got on the pill thinking it would help me. But I’m still seriously afraid. I feel so bad for my boyfriend because this has caused problems when it first started. He said it doesn’t bother him now because he’s learned to mature and understand. But I know it bothers him. He’s young and I know he’s a very sexual person. I want to enjoy Sex, but at the moment we only have it once every like.. 6 months. I’m almost 22, not even like 16 or something. It got to the point where I would cry for days after because I think I’m pregnant. I just don’t know what to do. Any advice?