Guide cluster
Cycle structure and ovulation timing
This cluster groups cycle structure, ovulation timing, fertile-window searches, and irregular-cycle fertility questions so users can understand the monthly rhythm first and then move into the right calculator.
Execution path
Use one monthly map to connect ovulation, fertile timing, and safety margins
Use this path when the user wants a usable fertility range, ovulation estimate, or cleaner cycle structure instead of a vague biology answer.
- Anchor the month on the last-period start date and current cycle length before talking about ovulation timing.
- Let fertile-window and safe-period pages branch from the same timing logic so the cluster stays coherent.
- Move into irregular fertility pages when the cycle stops behaving like one fixed monthly pattern.