No idea what I did

I pop my elbows all the time by pushing them with my palm facing me then straightening them out. I did it to my right arm and it was fine. Then I did the first one to my left and it popped but hurt really bad. Then I noticed it hurt to move it or touch it. I can't extend it all the way and I just did it a few hours ago and made sure to try and keep moving it. It feels the same as my right elbow did about 2 and a half years ago. It won't pop and hurts in the same place. That time though my karate instructor twisted my arm around and I fell out of my chair and my elbow made a loud pop just like the one I heard tonight. We went to the clinic and they put me in a half cast and sent me home because they didn't know what was wrong. A week later I took the half cast off because it was causing more pain and tried to pop my elbow and it felt like something popped back where it should be and felt great. I think it was out of place just enough to hurt but not be noticed on x-rays. That same pain is back and I don't plan on going back to doc for it again because they weren't any help the first time. Can an elbow actually dislocate enough to hurt but not show up on x-rays? I plan on just icing, resting and taking some meds until it feels better. Should I be doing something more or is that fine?