I have something like a depression surrounded by redness on top of upper gum over the molar. It hurts when touched by food and does feel like a canker sore (have had them before). However there is a bit of change in colour a few centimeters over that. (on the upper palate) changes from Normal pink to very dull reddish colour. No growth there though. The problem is I'm a hypochondriac and am scared of oral cancer. I'm 18 only and just want someone to reassure me that the small patch of discolouration is common (and was perhaps always present in my mouth)