Birthcontrol and conservative mom

I'm 17 and sexually active, I used to be against the pill but now I'm starting to think it's the more responsible solution. I've only had one partner so we're not worried about stds, but we want to be married before having kids. My moms extremely conservative so theres no way in all hell she'd get me the pill, so my question is how do i get it and where? How much will it be? And do I have to have my mom sign anything? Also we've been sexually for about a year now.