I have random aching In my bones in my legs and arms?

I'm fourteen but ever since I've been little I have this sensation that can only be described as a dull but painful ache in what feels like in my bones. I thought it just happened in my joints in which is usually the case but it can happen in the middle of my arm. Sometimes it's so bad it makes me cry. My mom always told me to take anvil but it never helped. I've tried to explain it to the doctor but they just kinda brushed it off. Any ideas of what it could be? It seems to occur at random.