I have this nagging soreness above my left rib cage- right below my left breast. it only bothers my when i cough or blow my nose. ?

Costochondritis: Sounds like an inflammation of the cartilage between the ribs called costochondritis or tietz's disease. Heat packs and antiinflammatories are helpful. If symptoms continue you should see your doctor.

Check with your doc: This could be nothing or the starting sign of something serious such as a heart or lung problem. Better be safe.

Irrritation: Might be slight pleural irritation or hairline rib fracture ct scan of chest or ribseries needed take a cough suppressant with Codeine would help the pain and suppress cough, nasal supray , so that no nose blowing, must see a pulmonologist( lung m.D ).

Getting over a cold?: If you've recently had a cold with a lot of coughing, you may have strained some muscles in your chest wall from all of the coughing. This should gradually resolve over time. If it doesn't, or if it seems unrelated to a recent cough or other musculoskeletal injury, then it'd probably be a good idea to get checked out.