there's mucus in your sinus and you may not feel it because they are sticky. while they are there clinging to your sinus linings, they serve as perfect nesting place for bacteria inside. that's why you sometimes feel feverish cause your body is fighting the bacterial infection going on inside. until your body gives up and you will have a full blown infection and that's the time you'll go to your doctor. at the same time, you will develop headache, clogged nose and sometimes ear ache cause of inflammation.
clean your sinus with saline wash 1-3 times a day. been there, done that