okay, you guys, let's hold the judgement. the birth control pill can be used for other purposes, like to make cramps and periods less severe. if you're uncomfortable telling your parents that you're having sex, you could use this approach.
but good for you for being proactive and protecting yourself. i would so much rather see a girl asking for help about getting on the pill than asking if she's pregnant. remember, the pill does not protect against sexually transmitted infections, so if you have sex you still need to use a condom too, plus it's extra prevention from pregnancy.
if your parents don't want to help you get on it but you still feel that you need to get on it, planned parenthood can help you get it for free or low cost, and confidential to your parents, and they also provide free condoms. i provided a link on their website so that you can find a clinic near you. they also have some tips about talking to your parents about this. good luck!