I was sitting down, then I got up, and the hip area of my left leg felt some kind of internal pain - like a nerve being pinched. Moving the leg, or placing pressure on it hurt as well. Finally, I tried shifting my leg around, see if I could undo whatever disjointing I had managed to do… and felt a tiny click inside, and everything was better.
IANAD (or Qadgop), but you might have dislodged (very briefly) one of the bones in your upper leg and placed pressure against some nerve. Did you hit it against anything or have a previous injury?
Could be your sciatic nerve getting pinched. Happened to me a couple times. It hurts like hell right in the middle of your butt cheek and down your leg. Try getting some more exercise. Hope it feels better!