What Causes Pain In Sternum And Dry Cough Post Recovery From Double Pneumonia?

I have had double pneumonia for 2 months(3 different antibiotics). I just went for a follow up...dr said lungs sound clear, I still have pain in sternum, dry cough. My oxygen sat was 92. She did not know what else to do for me but suggested a specialist......is this a necessary or do I just need more time to recover?