Hello. 62 Year Old Healthy Male. Developed A Dry Cough

Hello. 62 year old healthy male. Developed a dry cough three weeks ago. First night had mild fever (<100) but no fever since. Cough persistent since then. Has become productive in the last two weeks. Until yesterday morning phlegm green/yellow but now is pretty much clear. Have tried Musinex Expectorant, moderate success. Overall feeling OK. Have been able to midly exercise during the last two weeks. Deep breaths OK but seem to be a little more strained lately. No pain on deep breathing though.