have been for a long run today and had to end up walking half way home. Had a terrible pain right inside my hip, that then sent a pain at that base of my spine/bottom of my pelvis, and aslo affected the outer muscle of my upper leg and knee.Have been experiencing this for a couple of weeks now but today was really bad. Im due to run in the agreat North Run next week but dont know if I should. what does anyone think? how can I get this sorted?