I've Had A Cold For The Last 3 Weeks. The

I've had a cold for the last 3 weeks. The stuffy nose and the ear aches aches are gone but I have a CONSTANT cough with a wheezing sound. Occasionally a yellowish mucous will come out. I have not seen a doctor as of now. I also have a burning in my chest when I cough. Could this be bronchitis, pneumonia or the lingering effects of a bad cold? Should I see a doctor? I have an 11 year old son am I contagious?