How can you tell the difference between allergies and covid-19? does covid-19 have post nasal drip?

PND can occur w both: Allergies can present w stuffy/ runny nose, cough, sneezing, sore/ scratchy throat or itchy/ watery eyes. Symptoms of COVID 19 infection may include (but aren’t limited to) dry cough, shortness of breath, nasal congestion, fever, headache, sore throat, feeling tired, loss of sense of taste/smell, decreased appetite, nausea, diarrhea, vomiting, chills without or without shaking & muscle aches.