Hello,
Without examination it is very difficult to confirm a diagnosis, but the symptoms are suggestive of allergies to smoke or air borne allergies.Other possibilities may be recent sinusitis,nasopharyngeal problems, olfactory hallucination {(phantosmia)you detect smells that are not really present in your environment}and disorders in the smell perception centres.
In my opinion,a consultation of an ENT specialist or an allergist will be the best.People who are allergic to smoke can smell it even if a little smoke is present in their surroundings..
Hope it helps.Take care and pls do keep me posted on how you are doing or if you have any additional doubts.
You know I've read this complaint from many members. Consider checking out this link on this from the Mayo Clinic:
http://www.mayoclinic.com/health/phantosmia/AN01684
Best,
~PlateletGal