Have you noticed that it comes and goes with your menstral cycle? It sounds like you may have Cyclic Sciatica. Read about it. I was originally diagnosed as MP, but now know that I do not have it. I am going to a pain clinic next week to discuss a nerve block. My pain started over 11 years ago and would come and go. Since my last pregnancy 5 years ago, I have had Bilateral anterior thigh pain 24/7. The only medicine that helps is Ultram. It has been a life saver as I would not be able to work without it. The only thing that makes me think that it could be cyclic sciatica is that the pain is much worse with my periods and before a bowel movement. So there definitely is something within my pelvis causing it. I work as an OT and with the help of my coworkers we believe that this is the closest diagnosis to match my symptoms.
Some causes of Cyclic Sciatica are pregnancy and endometriosis. If you feel this may be what you have talk to your OB/GYN or which ever specialist you see. There are several ways it can be treated depending on the cause. One easy treatment is to take birthcontrol pills continuously so that you do not have a period. This stops the pain for many. If it is caused by endometriosis scar tissue, a surgery might be needed. Hope this helps.