What Causes Pain In Lungs After Treating Bronchitis?

I had bronchitis a 4 weeks ago, it has taken a while to get over it. While the coughing, congestion, and tightness in my chest has been resolved, I still have pain in my left lung when I breath deep or lay on my back. It's even tender when I press against it. The pain has localized over the last two weeks to small area, size of a softball in my left upper lung area. I have had no fever, no weight loss, no fatigue, and no loss of appetite. Could this be cartilage or tendon pain from the excessive coughing a few weeks ago ? Could this be some lingering pleurisy issue, or perhaps a lung abscess ?