Two weeks ago I was diagnosed with pneumonia. The week prior to that, I was in bed all week with a severe case of flu with a fever of 103. The fever went down and I went to the clinic, where I was prescribed Levaquin which I took for seven days. I took my last pill last Sunday. I'm still coughing and in the last couple of days I've felt a tightness in my chest and am getting short of breath more easily. What should I do?