I was sick for a few days. I was weak, faint feeling, had a soar throat (not for long), achey back and knees, occasional chest ache, and a slight fever (101). This started on the 26th. Today and yesterday I felt fine. This morning I caughed up a little yellow phlegm. I thought this was good. I knew it meant that if I had "crud" in my chest it was decongesting. I asked someone and they said yellow phlegm was a sign of infection. If I feel ok, with a little tightness, can I still be sick. Does anyone know what this is?