I was just talking to my masseuse who is in the office at present - it's massage day here at work today. She asked if I'd had any pain recently and I told her about the pain I had from my hip flexors that went around the sides. I have had sciatica prior to being pregnant and have had no issues since she's worked on me. Anyway, she mentioned an easy strengthing exercise. Lie on your side with knees bent and a small cushion between your knees and just open and close your legs, like a clamshell. Lifting the top leg of course, and then bringing it down....it's not meant to be strenuous. It's the gluteus medius (I think that's what she called it) and it's attached to the hip flexors and gluteus maximus. She said the medius is a lazy muscle and doesn't really provide much support unless it's exercised. So I'm going to start doing those to help build up some strength. She said it could help in the later stages of pregnancy with having all of the muscles in that area working together.