Hip/Thigh Pain? Help!?

Hi im a female 14 year old that participates in track and cross country. I have a sickening pain in the side of my thigh that hurts after i do a hard workout in track. The day after it hurts, and i have been heating/icing/rolling my leg. I tried to rest it, but that didn't work. I was told to run through the pain by the school trainer. We originally thought it was my IT band, but i have been stretching, and it hasn't gotten better. I also have pain in the center of my butt, like the hip joint? i don't know. and also on the very top of my leg, perhaps where the muscle or tendons connect to the bone. Has anyone ever had this pain? Can anyone diagnose it? I appreciate any help i can get...and i prefer personal experiences, not just sites. Thanks so much. It has been going on for about 4 weeks-hurting on and off-and i really need some help. Thanks.