The variation in cycle length is attributed mainly to the timing of ovulation. Nevertheless, the length of the luteal phase may also deviate significantly from 14 days. For example, the luteal phase length was between 7 and 19 days in a sample of 28 day cycles.

What does it mean if your luteal phase varies?

A long luteal phase may be due to a hormone imbalance like polycystic ovary syndrome (PCOS). Or, a long lapse since you ovulated could mean that you're pregnant and you just haven't realized it yet. The length of your luteal phase shouldn't change as you age.

Can you have an irregular luteal phase?

A luteal phase defect can happen to you if your ovaries don't release enough progesterone, or if the lining of your uterus doesn't respond to the hormone. The condition has been linked to many health problems, including things like: Anorexia.