The period of time between ovulation and the first day of the menstrual period is known as the 'Luteal Phase' sometimes referred to as the 'Post Ovulation Time'. The length of the luteal phase is fixed and in the majority of women lasts for exactly 14 days. This number can vary with some women having a luteal phase of 15 or 16 days and others as short as 12 days, but, whatever the length of your luteal phase, it is always constant being the same number of days long, month in - month out... even if you have irregular periods. If you do have an irregular cycle then the 'irregular' part of the cycle is the first part up to ovulation. Once ovulation has occurred then your period will start exactly 14 days later (or however many days long your luteal phase is) unless of course fertilization has occurred.