What can I use for cough if I don't have a doctor?

Many OTC. Many over the counter medications can help with cough - if you are concerned you should speak with your neighborhood pharmacist. Many people forget that they are very well trained in pharmacology and have a wealth of information.
Guiafenesin. Guiafenesin can help break up mucous and "loosen" the cough but it is much more important to figure out why you have a cough. See your doctor and the describe the pattern of the cough, what makes it better or worse, how long its been there, is it worse at night.