How to tell religious parents I want to have sex

Hi guys I just posted a while ago about my mom finding hickies on my boob from my bf and since I am 18 I want to tell them I want to start having sex but I’m scared of what they might say. I know it’s my choice but they’re so strong on waiting until marriage and they think it’s bad not to (even though they didn’t) and I want to be able to go to them to talk to them about this kind of stuff and ask to get on birth control because they also fear I might get pregnant. I don’t share their views and I don’t know how to tell them this. I know you guys will say to move out and stuff but that’d honestly make life pretty hard since I’d miss them and I’m just starting college so I don’t think that’ll happen but if push comes to shove I will try to move in with my bf but I don’t have money either :/. Any advice would be super helpful thank you 🥺