First the caveat, no one without looking at you can tell you what you have, and that person should be a doctor or dentist trained to do so. Having said that, I will offer you my personal observation, one of a non doctor who is well informed, but is not licensed to give out medical opinions. First, USUALLY only those things which have not resolved within 2 weeks should be considered suspect. There are all kinds of bumps that come and go in a persons mouth, and the majority of them are benign. Second, the location that you are describing is not one of the most likely locations for oral cancer to appear. If the bumps are clear, and of short duration, and continuing to grow, they are most like a simple thing called a mucocele. There are tons of little ducts in the linings of the mucosa in your mouth that secrete moisture. Sometimes one of them gets clogged up, and the clear fluid backs up right under the uppermost layer of tissue causing a little blister like bump. It eventually ruptures and the bump and all goes away in a few days. If you have these bumps that you describe for more than two weeks, have your dentist take a look, and to put you mind totally at rest, he can do a very simple biopsy to have the tissue examined by a pathologist.