Cough at 4 months!

Hi mga momsh, ask ko lang what should I do if my baby has a cough? dry cough kasi sya and base sa mga articles na nabasa ko, pwede rin daw itong Teething coughing.. 4 months na kasi si LO and may possibility din na nagngingipin na siya. Anyway, what medicine should I buy for her? #pleasehelp #advicepls #firstbaby