How can i tell that i am almost full indian?

My grandma's grandpa isl 100% blackfoot/blackfeet indian(on my mom's mother side) and my grandpa look almost like a full blood indian we don't know what tribe he is though he's either Cheyenne or Cherokee. my mom has got really dark skin and black hair dark eye's high cheek bone's and my grandpa's got the same but he's darker a little and has blue/green eyes. me my self have the same as my mother but i don't have to skin that dark anymore i have a tint but i am sick with anemia and lupus and lupus is also another native american trait i would love to find out for sure. i would be so happy cause i love all the indian cultures i studied half of them. if i have to do the blood test and where do i go to get it done at?