Birth control

My min is totally against me being sexually active, she won't even let me lay on the living room couch with my boyfriend. I am completely and totally in love with him and we both want to take it to the next step. We've already done a few things, like oral, fingering and handjobs. We don't want to do anything if it won't be safe. We have two condoms that a friend gave me. We are both 15 and cannot drive so we can't but condoms or anything. How do I get on birth control without my parents knowing? Any tips of staying safe, other than not doing it?