Initiation the conversation

okay so I'm 19 and I want to start getting on birth control, the thing is without insurance I heard it can be crazy expensive. I'm under my moms insurance and I want to talk to her about possibly getting it. I don't know how to initiate this though or what even to say. she doesn't know I'm not a virgin anymore and I've never introduced her to any bfs because they've never been serious. any help or tips would be much appreciated