Hello ! Maybe you should not have to be concerned about that because during the time you had fever and runny nose there was an inlamation in your nose olso and during the cough you may have demaged some little blood vasels in your nose what cause the redness/brown color of your secretions. In this case you should only use some nasal spray like IALOCLEAN nasal spray. But, if you have a heaviness in your head with stinky secretion in your nose you probably can have a Sinusitis and in that case you should see an ENT doctor to take some antibiotics.