Mystery of the Missing Muscle

On Monday we did a lot of kicking and I knew the I'd be feeling it on Tuesday. I did, but not at all in the way I was expecting. Last night, I felt it as soon as I started warming up. Each time I cetitui-ed on my right I felt my hip sort of pop and click back into place. It didn't hurt exactly (thought not particularly comfortable), it was just a totally bizarre feeling that each time left me trying to figure out what the heck just happened. What it feels like, is that there used to be a muscle on the front of my hip socket holding everything in place and suddenly it isn't there anymore, and the joint is just popping around however it pleases. What's going on in there? Wondering if anyone else has ever had this. Is it a sign that all that kicking extension has pushed me to a new point of flexibility? Or is one of my hip flexors on vacation someplace? I guess so long as it doesn't hurt, I wont worry. It sure gives popping a whole new meaning. :)