How do you count luteal days?

Luteal days are counted from ovulation until the start of your next menstrual period. To determine the luteal phase, identify the day of ovulation, which is typically around 14 days before your period starts in a regular cycle. Count each day following ovulation until your period begins, with the first day of your period marking the end of the luteal phase. The luteal phase usually lasts between 10 to 16 days.