concern ?????

Ana • Im A mother To A Little Beautiful Princess Named Paola Yamilet Hernandez 👑 🎀 👼 Born June3rd 2016
My daughter is 9Months old . She been having a cough , running nose , and mucus congestion for over a month . First time I took her to her doctor they gave her certizine other times I have took her in the don't give her anything . What can it be ? Or what can I give her over the counter ?