12 year olds aches and pains

Answer 1

I'm not exactly sure what you mean by that, but I'll try to answer.
Part of it is just growing up. Maybe you are growing in the areas that you feel pain. Maybe it's the sports you're playing that is hurting it, or maybe you injured something and need to get it checked out by a  doctor. Be sure to talk with your parents about it and schedule and appointment as soon as possible.