How to talk to my mom?

Cassie

So me and my boyfriend started talking about having sex soon, and I want my mom to put me on birth control but idk how to talk to her about it..I’ve tryed to bring it up to her before multiple times but she just keeps saying that I should be with the guy for at least a year and how she Doesn’t want me to.. Any advice on how to talk to her about it? I need birth control to have sex with my boyfriend, to me it’s really important to be extra safe..