birth control

my boyfriend and i talked and we decided we want to start having sex, but i want to start taking birth control before we do anything and he supports that. the only problem is that my parents would never let me. they are very overbearing. they insist on driving us to and from our dates, they ask questions about what we’re gonna do. when we’ll be ready to get picked up, etc. his mom works at an OB/GYN office and has offered to make me an appointment, but like i said, my parents are overbearing and would never let me probably even go near an OB/GYN office. how do i go about getting birth control and paying for it without it being crazy expensive without insurance