Almost 3 weeks ago I developed cold/flu symptoms eg fever, night sweats, sinus pressure/congestion, coughing, nausea. That lasted about a week, as soon as those symptoms started to fade away I got a sore throat, but only on my right side. That was 2 weeks ago and I still have the sore throat. What gives? Again, all other symptoms are gone except for the sore throat. What could this be?