It's called Taking Charge of your Fertility by Toni Weschler, it's so helpful when you're TTC or when you're not! It would solve so many questions in this community! All you have to do is BBT chart, check cervical fluid, and cervical position, then you'll know if you're late, or pregnant before you waste a test!! I don't check my cervical position but I always know according to my temp that it's dropping and aunt flow is coming. It's been my lifesaver lately! I used to waste so many tests!