What Causes Pain And Popping Sensation In The Chest Upon Coughing?

Been dealing with seasonal allergies and coughing for three weeks, which is slowly subsiding. Strong coughing fit a few minutes ago led to a popping sensation on left center side of my chest. Popping sensation was accompanied by a sharp stabbing pain strong (gonna say 7 on a 10 scale) enough to drop me in surprise to one knee. Less of a sound, and more of someone snapping an imaginary big rubber band from the inside if that makes sense. Stood up after a minute, and the stab feeling has subsided to a steady 3. Probed my chest and the sore focal point seems to be right where the edge of the sternum would be. I can poke the exact spot and get a 5. Leave it alone and it subsides. I ve cracked ribs in the past and this feels similar. I m taking ibuprofin and putting ice on it next. Nope, no weakness or pain in my jaw, chest, left arm or anything like that. Think I stretched a muscle or ligament.