I’m also four months post surgery, and doing well. But at the one month mark, I had a dry cough that was getting worse. I called my surgeon’s team, and they told me to get a CT scan. The scan showed lot of fluid surrounding my left lung. I was readmitted to the hospital, and they placed a drain in my left side. More than a liter of fluid was drained out over two days. Fluid can build up after a traumatic surgery such as ours, and it can squeeze the lung causing dry coughing. After that treatment the cough was gone immediately. I would recommend you call your surgeon immediately and let them know what is going on. Good luck in your journey.