Hi,
One of the general pieces of advice you will find on this board is that if you have a lump, red or white patch, or anything unusual in your mouth that doesn't clear up in a couple of weeks, you should see an ENT specialist to determine if anything is awry.

Given that you asked your doctor to feel the lumps and his response was that he couldn't see anything, I would strongly recommend that you see an ENT specialist. Personally, I'd change doctors as well, but that's your call. Best, Sheldon