How to ask to get birth control

I need advice! My parents are super conservative and I am not close to them in the least bit. Also my dad has literally disowned me for 5 months for simply getting a tattoo so I'm very scared. I want and probably need to get birth control but my mom and dad most likely will not let me. But Im having regular sex and my periods are not at the same time at all and are super long (up to 10 days). So is there a way I could get the pill without my parents knowing or do you guys have any suggestions on how to ask without them disowning me?