Hereditary hair loss is common, what should I do about losing my hair? I'm only 15?

I am only 15, I am suffering from thinning hair. You could see my scalp, and I don't know if I should go to a dermatologists or wait until my hair is completely gone and then do something about it. My dad has no hair (balding) and I dont want to end up like that. What should I do?