Had flu 2 wks ago. dr said i had bronchitis and gave biaxin 10 days. felt much better. after stopping antibiotics cough has come back. how come?

Cough: It is not uncommon after the flu to cough up to month after but usual every few daysis better than the last few days.Sometimes the lining of the lungs-the pleura is irritated and aometime the bronchi are.I would be more concerned if you are not feeling better,have a fever this far out,short of breath orthe cough fails to continue to get better.