Fear of getting pregnant

I have a Huge fear of getting pregnant.. My boyfriend and I have been wanting to have sex for a long time, but I'm so afraid that I'll get pregnant. And it's not gonna go away when I get older. I don't want to be pregnant, ever. I'm not just afraid of being pregnant because I'm a teen, I just don't ever want to be pregnant or have a child. But I have a very high sex drive and I want to have sex, but I don't know how I'm gonna be able to have sex without constantly worrying about it. Does anyone know a form of birth control that I can be on without my mom having to sign for it or know about it? I want to use condoms and be on birth control