Just Finished A Box Of Mucinex 12 Hour, Mucus Is

Just finished a box of Mucinex 12 hour, mucus is a bit yellow. Have had this about 10 days, began the Mucinex last Sat., also using Flonaise, tylenol. Much better, but do not want to relapse. Dr. gave me a Z pack perscription to fill if I need it--don't think I'm that bad. No fever or sinus pressure, pain. Should I purchase another Mucinex or see what the next day or so brings?