While doing bicycle crunches, the joint between my pelvis and left top thigh bone doesn't seem to be rolling smoothly. I always hear kind of a click sound when I drop and extend my left leg. This doesn't happen on my right leg though. I am doing the bicycle crunch incorrectly/ have other ppl experience the same thing too. How serious is this and should I get it checked out, or will it just go away when i do more bicycle crunches?