I have had a stuffy nose for 7 days. Not runny but just stuffy. Initially I had nausea, tiredness and aches/pains in muscles and joints. I have had numerous COVID, influenza and multiplex Respiratory PCR tests but no viruses detected. There is no fever, sire throat or cough. I don't have any allergies or itchy eyes. Why are my respiratory label tests returning normal when it sounds like some sort of virus.