My 4 month old baby is sick.....?

Hi, i am a first time mother, my baby got sick, she has an ear infection but when the pediatrician checked her her chest was clear, her nose is congested and now when she coughs it sounds like she has secretions from the same congested nose coming down. The pediatrician gave her amoxilin and clabulanate with potium 1.5ml every 12 hours. Just wanted to when when did your baby get better and how was it treated? Thanx