Napro is all about regularating your hormones, surgically correcting things and a whole lot of patience.
When I first started seeing this Dr. last Nov she had me do a unmedicated hormone workup which consisted of Cd3 BW and ultrasound and then they did BW every other day the entire cycle. They also did a 7 dpo ultrasound to check for a ruptured follicle and tri-phasic lining.
I thought my numbers appeared pretty normal that month. My cd 3 fsh was 7, my e2 rose to 264 at O.
Somehow based on all my numbers she could tell that I was having a sub-optimal ovulation. They also rechecked my fsh and lh at 7dpo. Haven't figured out what that shows, maybe it's a resting fsh/lh ratio thing, not sure. What it did show was that my progesterone levels peaked at 8 on 5 dpo and then quickly fell. She referred to it as a Type 3 luteal phase deficiency.
There's a book called The NaPro Technology Revolution: Unleashing the Power in a Woman's Cycle, I read it recently which explained the different LPD types and a number of other fertility tests in detail. A lot of the information was old news since I've been through years of this already, so I wouldn't pay money for the book but I was able to get it on an Inter-state library loan.