The length of menstrual cycles may vary from cycle to cycle (1,2). The menstrual cycle is not always perfectly predictable (1).
Your body is not a clock there is variation in the menstrual cycle There are also three phases in the ovarian cycle: follicular (before ovulation), ovulation (when an egg is released from an ovary), and luteal (after ovulation) (1). There are three phases in the uterine cycle: menstruation, proliferative phase, and secretory (before period bleeding) (1). Different events occur during each phase.
Both the uterine cycle and ovarian cycle are divided into different phases, in other words different stages (1).