Something felt like it popped in my leg today when I was playing baseball at about three o'clock today and the pain is excruciating.
The pain is between my thigh and hip, what is it?
Sounds like one of your hamsting tendons..
Ice it and call your doctor
It could be just a snap of the ankle. It might not be serious issue but you will have to place some ice on it and make sure that you see a doctor for further examination.