Did you know that your menstrual cycle has three phases?

Glow

The average menstrual cycle ranges in length from 21-35 days and consists of 3 phases: the follicular phase (an egg develops and prepares for ovulation), the ovulation phase (the ovary releases one egg), and the luteal phase (hormone levels decrease if the egg is not fertilized). The luteal phase lasts 14 days in most women, so when your period is late, it's usually due to a change during your follicular phase.

Source: Cleveland Clinic