Thick phlegm globules (clear mostly, white sometimes) , dry but deep cough, mild temperature, 4+ weeks. doctor hears nothing in chest. what is it?

Atypical pneumonia: Atypical pneumonia is an infection in the lungs caused my unusual bacteria like mycoplasma or legionella and where the symptoms differ from the classic ones. Therefore, it's often harder to diagnose. The antibiotics used are different and if it becomes severe it may require hospitalization. If you're not getting better, ask your physician what he /she thinks and if a chest x-ray is warranted.