Mom won’t let me start birth control

I’m 16 now and I’ve asked for birth control before I got a boyfriend bc I thought it would help my drastic mood changes during my period and acne and my mom said no. We’re not a religious family she just believes that I don’t need it. I’m definitely ready to have sex and if not now in the future. I’m really just trying to be safe and look out for myself but she insists it’s only for people that experience really bad period symptoms. It’s really frustrating because it’s like she’s trying to control that aspect of my life. I’m really not out here trying to get pregnant. I know she’s just looking out for me but she was perfectly fine with my sister losing her virginity at 17 and with me it’s completely different (I’m turning 17 this year btw) any advice?