It is very difficult for us to pinpoint exactly what you got. I suggest you go see a doctor and have him/her take a look at it. It doesn't sound good from your description there. The popping sound is often a ligament or tendon rubbing over a bone.
Sorry for the late reply. If you still haven't gone yet, you can just go visit your family doctor for now and see if you need an xray. May be the doctor will refer you to see a specialist. Good luck.