I don't think what I had was a cold sore either now thank god . I don't think it was a canker sore either it didn't hurt . I cant really explain it and i don't have any pictures but it looked like blister like a little bloody scab. only lasted a day and no pain . I was gonna go to dermatologist but , right now I have nothing to show . i don't think herpes last a day to heal and if i did have it on my tongue I would guess it would hurt like hell