15-16 days ago, I got a sore throat, I wasn't sure if it was the cold or allergies but I felt briefly fatigued for a few days and then felt ok - except that the post nasal drip (clear), congestion and productive cough have all continued - nothing else no headache, no fever, no pain. I was taking Nasacort, then I switched to Muscinex, but nothing seems to help. It doesn't get any worse, but doesn't seem to be getting a lot better. exercise seems to aggravate it. Can congestion last three weeks?