Can you post the pic that would be helpful. Ulcer usually are caused due to bacteria ( H. Pylori) associated with stress or
vitamin b12 deficiency if you are a vegetarian if not caused by trauma ( if u are hurt) . Consult your dentist if it just a ulcer or lesion that is of any other origin. It's best to be sure than to be in doubt so pls meet a dentist soon.
Health Tips
please upload the pic of ulcer and nearby area for further diagnosis