I have a cough and I observed that I dont produce that much phlegm now after 6 days but I feel some heaviness in my chest. What is it?

Chest "heaviness" The only way in which this can be answered is for you to be examined, your chest auscultated with a stethoscope and possibly undergoing a chest x-ray if felt necessary by the diagnosing doctor. If this continues or you have any trouble breathing see somebody ASAP. Good luck and hope you feel better soon.