Your Fertility Signals by Merryl Winstein (1989, Paperback)

This book is a must-read for all women. For starters, I have taken natural family planning classes taught by Phds (which can be expensive), and this book covered everything that I had learned in those classes. It gives detailed examples of how to track your body's natural signals, and gives the reader a very clear understanding of how to interpret their fertility signs. It also touches on such individual aspects to the female cycle as when breastfeeding, irregular cylces, etc. Great!