I woke up with a fever yesterday and also felt a canker sore like feeling at the back of my jaw, between my upper and lower teeth.  Its now gotten bigger, size of a big pea and it can move.  Does not look like a canker sore, which I am prone too.  Any ideas?
Thanks for your query, I have gone through your query, the ulcer could be an authors ulcer or herpetic ulcer (since you are giving history of fever) or traumatic ulcer. Consult your oral physician to rule out these things and if I am your treating doctor I would have advised you to take topical anesthetic, analgesic and topical steroids (triamcinolone acetone 0.1%). If the ulcer doesn't heal in two weeks then it can be biopsied. I hope my answer will help you. Take care.