I keep wondering the same thing. We certainly weren't ready when we went NTNP, and really aren't entirely "ready" now either, him especially. I am in the wave that says "you are never really ready!"
But we have been NTNP for 13 months. I have PCOS, along with mental disorders and a few other things I do not care to get into. I feel like the odds are against me, but having it be a surprise is what I would really like the most. I took one of those First Response fertillity tests, it came free in a box of preg tests. It says it only measures reserves, and the ability to release eggs etc, and it came up positive, so at least I have some eggies in there!
Every month I hope its THE month, I had a psychic reading that said it would be last month, but it did not happen. The month before I may have had a chemical.
Keep your chin up and don't get too wound up if it hasn't been a long time trying. You will get there!