The Pill

Hi guys. I’m gonna be 16 in three weeks and want to go on BC to help me out with my period (I’ve only had it for a year and a half but it’s leveled out to 7-8 days) and if things get serious with my boyfriend I want to be extra safe. My questions are:

1. How do I get it?

2. How do I get it without my mother knowing (my 28 year old sister would help me out)

3. Any info in general on how it works, how safe it is, or any other information on it.