Hi, I have a light white patch in the back of mouth, it does not look like Leukoplakia or oral thrush. I saw the doctor three times in 2 month time, first time they took a swap to see if it was a strep throat and it was not, second time they said its an ulcer and should go by it self, third time the referred me to a specialist and wont be able to see the specialist untill one month from now. There is a slight stinging pain when i swallow. Could you please let me know what it could be. p.s it is not a thick white patch its very light in color.