Fighting with myself

So I am in a serious relationship and we’ve been together for almost a year now. I’m really struggling with intimacy. I was a virgin when we first met and we both really enjoy being together and having that intimate relationship. We had sex for the first time in May, I wasn’t on birth control then but we used a condom. I got really nervous thinking somehow I could have gotten pregnant. A month and a half later I have gotten over my freak out and got on birth control. We had sex two more times with a condom and he pulled out and I was fine until the week of my period. I think my period was different due to my body getting used to the birth control. Once again I had another freak out thinking I still could have somehow gotten pregnant. We haven’t had sex since the end of June but have messed around a lot. I know that it’s almost physically impossible to get pregnant that way but I can’t help think negatively. My period is due this week and on Friday I started having unusually bad cramps and my forehead broke out worse then ever. I know that it’s impossible almost but I just can’t help thinking that it could happen.

How do I get over this fear and actually get to enjoy our intimate relationship? I know that eventually this will cause major problems (not that it isn’t already)