Was on hrt for about 2 years first time she for pregnant. Also had ran several cycles and was at the end of a deca/test/proviron cycle when it happened. I was on hrt for almost six years and have had more cycles then I could count the second time she got pregnant. We tried for several years so I finally have HCG a try. I was using 500iu 2-3 times a week. I tried to maintain an every other day routine but with my work and travel found it difficult to maintain. My dosing wasn't just a random number I picked out of my head.
I tried to follow this protocol because it was a control scientific study with control groups and was proven to work:
http://m.jcem.endojournals.org/content/90/5/2595.full
Edit - btw, I never came off hrt at anytime while trying to get pregnant. Once I went with the HCG it was literally less then 2 months before we found out she was pregnant, and of course she was 5-6 weeks along by then. Don't give up hope.