What Causes Chest Discomfort After Recovering From Pneumonia?

Hi. Earlier this month had mild pneumonia. Prescribed Levofloxacin. Bad reaction. Changed to Amoxicillin and Clavulanate. OK but stomach reaction. Felt better. Went on cruise to Caribbean. Felt fine but a little weak at beginning of week. On return, felt some chest discomfort but no fever, chills, etc. Should I return to MD to see if pneumonia returned? or should I go back on meds? Male 67. Live in NY.