I recently was having issues building my lining for a mock cycle. What seemed to work for me was when they switched my estrogen from oral and vaginal to delestrogen injections. Have you tried switching around estrogen delivery? I also had added viagra 4x a day, Vit E 1000 I.U., baby aspirin, and pentoxiphylline 2x/day(another med to increase blood flow, has some side effects though)that week when I had a better lining. My accu had me doing moxa at home 2x/day. And with the advice from many on this board I also did aerobic exercise, drank alot of fluid, mayan massage. I believe it was all helpful, but in the end I saw the best improvement when I changed to injections and added in the new meds. I really really hope that they find what works for you. Many here have had experience with this here, so I'm sure more will chime in. GL to you and let us know how it goes.