Hi dr, i have pain in the left side of my chest, right by my breast. its worsed when i take deep breaths. i have to poke hard to take deep breaths?

Costochrondritis?: At your age and in the absence of other risk factors, I think you might have sprained your chest cage. It will take time to heal but you may try heating pad to see if it offers any relief. NSAID for a couple of weeks may help. Most important-try to avoid the activity which might have caused it . (assumed that you have not fallen and broke some of your ribs)>