Have pain in my muscle under my left rib cage, pulled or did something at work, it also hurts when i breathe and cough, i don't think it is a broken r?

3 possibilities: Costochondritis: the place where the bony rib meets the cartilage rib can become injured and painful. Not broken unless major trauma or defect in rib. Intercostal muscle strain: the muscle between the ribs can be torn and painful. Pleurisy: The lung tissue can pull away from the chest wall and become painful. All 3 are benign and should heal in 4-6 weeks. NSAIDs like Advil (ibuprofen) will help.