Hello. For the past two, almost three, months I have been getting cankers sores (always in a different place). For the most part I only get, at most, two at a time. They will heal in about 2 weeks or less, I ll have a couple days peace, and then I start to get more again. They definitely look and act like canker sores. I am on the Depo-provera shot (I went on it June 29th). I haven had canker sores like this before! I m 26 with a pretty good medical history. My stress levels have been better, if not normal. As far as I know it s not a food allergy , nor have I introduced anything new into my diet . Could the shot be causing the canker sores? Could there be something else causing it? Thanks!