I am having the exact same symptoms. I thought maybe I was pregnant but have had everything from 10 urine tests to an ultrasound and everything comes back negative. I have a tight feeling on the lower right side. Please let me know if you have had any responses about these symptoms.

im almost sixteen and have almost the same problem (no two week period, only a week for me....but its awful)there is noooo chance im pregnant at all! its really incomfortable to lay on my stomache for an extended period of time, it feels like there is a rock under my right side. it also hurts when i run (its not side stitch im possitive)some other websites said kidney stones and ulcers. an ulcer is a possibility but i think it would have caused a bigger problem after a year.can teens even get kidney stones? it also hurts when im laying down if i suck in or put pressure there, its only my right side though.