All my mom and I do is fight..I want to live with my grandma..?

My mom has always had full custody of me. We don't get along anymore and I decided I want to live with my grandma. (She's my Dad's mother) I'm 15, and I thought since I'm only three years underage I can decide where I want to live. My question is, if i do leave home to live with my grandmother can my mother force me to come back home? Or do I have a right to live with my grandma if I chose so? I'm not sure if I'm going to go through with it, but I want to know in case my mother and I get in another fight, since I'm pretty much done with her.