I have stomach cramps and bad lower back pain, its not pregnancy or period cramps and has been happening for 2 week, what else could be causing this?

Confusing . Stomach cramps and low back pain are not usually associated unless you mean low abdominal cramps with low back pain. In that case it can be from the bladder (like an infection) or from your uterus (pelvic pain) unless it is 2 separate problems happening at the same time. Give us more info.
Difficult to say. Any type of undiagnosed pain for two weeks is concerning. Go see your physician.