Upper Inner Thigh Pain

I started getting pain in my lower left back almost where the sciatic nerve is. I originally thought it was that until the pain went to the front of my inner left thigh next to my groin. It's not in the crease of my leg. It's right in the middle between the top muscle on your leg and the groin. It mainly hurts when I get up from sitting and start walking. It will subside while I walk and then come back while I'm walking. It's very strange and the pain effects the way I walk. This has been going on for a month or so. Any ideas?