I can totally sympathise with you. We started ttcing in 2003 and at the end of 2005 started all the tests. Everything came back normal and we were diagnosed with unexplained infertility. That didn't help me one bit. How do you fix something if nothing is broken.
Even though I was ovulating, I ovulated late in the cycle around CD30, so I was put on clomid for 6 cycles. I conceived on cycles 1, 4 and 6. Unfortunately, the first 2 ended in early miscarriage and the final one was ectopic and I lost my right fallopian tube. After the miscarriages I was checked for possible causes but again nothing conclusive came back and my specialist thought we were unlucky - you can say that again.
In October 2008 we had IVF and was lucky enough to be successful first time and had our miracle daughter in July 2009.
We tried everything, diet, vitamins, preseed, I think if someone had said to stand on my head and chant for 20 minutes I would have. The only advice I have is don't let it control your life and damage your relationship with your partner. We very nearly split up because of how it affected my life, our sex life was mechanical at best and all my time, spare cash and energy went on getting pregnant.
Fingers crossed that one month soon you will have that elusive BFP