I Am Taking 1 15mg Amphetamine Salts. I Started This

I am taking 1 15mg amphetamine salts. i started this about a week and a half ago. I have not changed anything about my diet, exercise, etc. But recently i feel as if i am developing an ulcer as i have had one in the past. is it possible that this new medication can be causing this? i cannot recall anything else that is new or different that could cause this.