Good evening! i been coughing for 4months now, i went to the doctor twice, the first time in ER, i had acute bronchitis, had shot, also antibiotic and cough med. they done chest x-ray. The second time, went to walk in clinic, chest x-ray again, they said my lungs is ok, another cough two kinds of cough meds. again. Is it normal that coughing will last longer?