Birth control

I'm 16 and I want to go on birth control. I'm not sexually active right now but I plan to be in the future and I want to be on the safe side. I want to go on the pill but I don't know how to bring it up to my mom. Most of my friends are on the pill for various reasons, besides birth control. I only get my period every 40 days or so, could that be a reason to go on the pill? Any advise would be really appreciated :)