I have a head cold and my nose is smelly. should i be concerned about a possible sinus infection? it happens when i'm not sick sometimes too.

Be seen: That is not unusual during an infection, but if it continues after your infection is cleared, then it should be investigated. You might need a ct scan of the sinuses to look for a polyp or even a tumor. This presumes that you do not have a foreign body in your nose, as that is a common cause of foul smelling nasal discharge.

Odor from nose: Infections in this area can block secretory flow from nasal cavities leading to stagnation and the overgrowth of bacteria which have side products that smell badly. You can try nasal decongestants, especially sprays or a netty irrigation. If there is local pain, bleeding or frank pus, you should see your personal physician or an ENT doctor.