Fertility Guides
These guides are educational, not medical advice, and they are not a form of birth control. For anything personal or time-sensitive, a healthcare provider is the right person to ask.
Three guides from OvulationCalc, the free fertile-window calculator. Each one stays with a single idea: how the cycle is arranged, what home tracking methods can and cannot see, and how to use an estimate without treating it as a diagnosis. They are explanations, not a care plan. Run your own dates on the calculator. The formula and its limits are on the about page.
The Menstrual Cycle, Mapped
The four phases, why ovulation day moves, the fertile-window biology that opens before ovulation, and the 21–35 day range.
Read the guide →Tracking Methods Compared
Calendar vs LH strips vs basal temperature vs cervical mucus — what each signal can and cannot tell you.
Read the guide →Using Your Results
Timing inside the fertile window, when a home pregnancy test can answer, and when to see a clinician.
Read the guide →