I am 18 years old. I do smoke occasionally. I have never had a cavity, but I do not have the healthiest gums. I don't floss regularly, but I brush my teeth at least once a day, usually twice.

Just the other day I noticed a slight bump on the roof of my mouth. It is slightly off center and I could only feel it with my tongue. Visually, there appears to be no discoloration and I can barely see it to begin with.

Any ideas on what this might be and any recommended courses of action?

Since, I can't see a my doctor or dentist until mid December, I am really concerned as to whether or not this is something that has to be dealt with immediately.

Forgot to add a few things that might be helpful....

It showed up a couple of days AFTER a dentist appointment and around the time which I also had a bad sore throat/cold.

Good morning sebispinetto,
lumps and bumps appear and disappear quite often and generally are not particularly serious but you should follow the standard advice and if the problem does not clear in three weeks see your dentist or doctor.
One other thing, since you only smoke occasionally you should not find it too difficult to quit altogether and that would be a smart move.
Keep Smiling
John