I caught a cold about a month ago, recovered and fine. i still have a lingering cough that produces clear mucous. i did go to the doctor couple days ago and she said my lungs were fine, etc. any advice?

It is reassuring that your lungs were clear, consider nasal saline rinses. This usually is effective in reducing post nasal drip. Watch for signs of shortness of breath and recurrence of fever.

Persistent cough after a viral infection is not unusual and can last for weeks, so please don't worry too much. It can be caused by some post viral inflammation, or post nasal drip (do you clear your throat often?), or even irritation from coughing. Cough suppressants like dextromethorphan can help, but it should go away on its own eventually.