Birth control/insurance

Hey ladies! I'm new to this, I was wondering a few things, I have Humana through the health market place for insurance , I need to get put back on birth control a friend of mine told me when I go for my yearly chexk up once a year it's suppose to be free? Apparently preventive care for women is free one time a year? And about how much does the pill cost for birth control? TIA:)