What Causes Sore Throat Along With Unproductive Cough And Body Aches?

I have been sick for almost 3 weeks. It started with a flaming sore throat and upper body achiness, eventually accompanied by a frequent hacking unproductive cough. About a week into the sickness it felt like I caught a head cold on top of the first illness, complete with lots of green mucous. That is pretty much gone now, and I feel quite a bit better but the hacking cough and constant feeling like I might cough any time have remained. At times I have coughed up stuff, but the cough is generally unproductive, though it feels as if I have stuff to cough up. Should I go to the doctor? Any other suggestions?