Hey Gidget,
Good questions. Sorry you have a cold.... That stinks. Well, it might take a while longer to get over it, but it might not. Sort of depends on the individual. I highly doubt they'll take you off your pred. I'd expect your doctor to run a few tests to make sure it's not bacterial in any way. Hopefully it's just a virus. Do you have any swollen lymph nodes? Do you have a history of strep throat or pneumonia? I'd contact them and get in to see them. They'll know exactly what to do and help you to keep it as a cold only, and not progress into something more serious, like bronchitis.
Have a good night,
Ginny