I'm right there with you. My fifth should have started today and as of right now... nothing! I have taken 4 pregnancy tests all which came back negative. I am now going to see a fertility specialist.

Have you tried Provera? It is used to stimulate the uterus to have a period? Or Clomid? Which is used to stimulate hormones and the growth and release of a mature egg. These will be our next steps. I am personally holding on to what a friend recently told me though... she had to take 6 negative tests before she got a positive. This was over the course of a couple months so maybe? Gosh I wish that was me.

Good luck and keep us all posted!