How can I get birth control w/o parent involvement?

I'm going to be 21 soon, so I don't have to worry about legalities, but I'm still on my parents' health insurance and I want to get some bc but not have them know bla bla bla. Is there any way I can get some not on the insurance without costing me an arm and a leg? Plus, any opinions on what method I should use? I would like to get the shot since it's one-time for a longer period of time.