Need help ID'ing mouth ulcer

[kalmiadave]

Hey all,

I have a painful mouth sore / ulcer (pic attached) that doesn't seem to be healing very quickly. I don't remember if this was initially caused by a food burn in the roof of my mouth. Location is upper right interior above my 2 back right molars. It's very painful and been about 5 - 6 days now and am wondering if I need to see a doc? Pic attached - help!

 

[Libra]

for how long its been there?
it wont be bcz of food burn if its there for a long time.. plus food burns are common on palate..