According to the FDA, you should take a test when you start having symptoms, such as shortness of breath, fever or chills, sore throat, congestion, new loss of taste and smell, or nausea and vomiting.
Contact a healthcare provider if excess phlegm persists for more than three to four weeks or if chest pain or wheezing occurs. How do you get rid of phlegm stuck in your throat? Drink plenty of ...