birth control

I'm 16 and my mom knows that I'm not a virgin, but I want to go on birth control incase I do have sex. I'm not planning on it anytime soon, me and my boyfriend are in a long distance relationship so. I want to ask my mom but I'm afraid she will think that I want to have sex but i really just want to be safe. condoms can break. my mother isnt really an easy person to talk to and we dknt really talk about periods sex or anything like that. of she says something is wrong then she better not catch you doing it. so i just need some help or advice please.