The book begins by reviewing the basic biology of the menstrual cycle, explaining the roles of key hormones like estrogen and luteinizing hormone. It then progresses to cover various methods for tracking ovulation, including their pros and cons, before exploring the impact of external factors on reproductive health. By drawing on research from reproductive endocrinology and clinical studies, ""Ovulation Window"" presents evidence-based information in an accessible manner, empowering readers to actively participate in their healthcare decisions. For example, hormonal fluctuations regulate the timing of the fertile window, impacting the effectiveness of natural family planning.