Nine days ago I had some type of lung infection that elevated by body temp to just under 100 degrees for about two days. During the infection and every day since, I have had a persistent cough. Originally, the cough involved a lot of congestion in my chest (and made sleeping very difficult at night), but now it is more a dry cough. Although I feel a lot better than I did a week ago, the cough has persisted. Should I be doing something about this cough?