Ulcers happen because of many reasons one of common reasons are stress or stomach upset ...do take care of that
But if u complain of reccurent ulcer at the same sight might be ur tongue is getting irritated from something at that area that can be deposits on teeth near to that area or sharp corner of teeth ...pls do ruleout that
Next Steps
do visit the dentist once
Health Tips
maintain oral hygiene
u can apply gel for ulcers but important to rule out the factor for exact cure