I have an inflammatory problem. Not saying that you have the same issue but I use to get pains like that all the time! The first time this happened to me every time I tried breathing the sharp pain/tightness in my chest would increase to the point when I thought I couldn't breath. This happened in the 6rh grade. after taking me to the ER turns out the lining/sac around my lungs were inflamed. This happens on and off over the yrs. and varies from my lungs to ribs...etc.
Acid reflux! Quite common, especially in women. I was around your age when I started getting it. (I'm 19 now) Stay away from fatty and spicy foods. Don't lie down within two hours of eating. Drink more water, and sleeping with you mattress raised using blocks underneath it. Good luck!
I remember I had pain along the lower edges of my ribs when I was around 12. I think it was a sort of growing pains. It was tenderness along the bottom edge of my rib cage.