I’m nervous 😬

I need some advice ladies. I’m 18, and my boyfriend and i are planning on losing our virginity’s together after graduation (which is in may). My mom knows and we’ve talked about this because we are super close like that and she’s told me to get on birth control the week before graduation. She also said that it would help ease my period if i were to get on it. My only thing is that my dad is the one who is in charge of my insurance, and i’m super scared to have this talk with him because he is very closed off and would probably have a heart attack if i asked. What do i say and how do i bring it up to him?