T.,
I am not a doctor either, but it sounds like you may be talking about your hip flexor muscle. It is the muscle that attaches your hip to your leg muscles, slightly below your hip bone. I was a college athlete and pulled this muscle on two different occasions. It is very painful because you flex that muscle every time you move your leg to walk. If it is pulled or strained, it will heal on its own but it will take some rest to get it healed. (which is tough because you use it all the time every day!) I would recommend though, that you do see a doctor just in case it is something serious. Good luck!