When I attempt to run, in about 4 min., I beging to feel severe pain near the left of my pelvis. When this happens I have to instantly stop for the pain is truly unberable. The reason I'm concerned is I have lost over half my body fat over the last 2 years(34% to 14.4%) and I fell I should be able to run longer distances yet I could run 1.5 mile in an avg. time when I was 32% body fat!!!! Does anyone know what it could be, if u need more info just ask.