How Is the Menstrual Mid-Cycle Calculated?

menstrual-mid-cycle-calculated Credit: PhotoAlto/Laurence Mouton/PhotoAlto Agency RF Collections/Getty Images

The menstrual mid-cycle can be anywhere from 12 to 16 days before the next cycle begins. The average mid-cycle time is 14 days after the start of the last menstrual cycle, according to the American Pregnancy Association.

The menstrual cycle is the process that allows pregnancy to occur in female primates and humans. It involves physical change to the uterine system that is necessary for the production of eggs. The normal length of the cycle ranges from 21 to 35 days. The average normal length of the menstrual cycle is 28 days. The menstrual cycle is marked by phases that run in a specific order:

  • Follicular: ovary prepares to release an egg
  • Ovulation: mature egg is released into the oviduct
  • Luteal: release of progesterone and adrenaline creates estrogen
  • Menstruation: progesterone levels fall

Menstruation serves as the marker for the start of the entire menstrual cycle for an individual. The menstrual phase itself is identified by a time of bleeding that normally lasts between 2 to 7 days.

Women interested in determining their mid-cycle point must keep a record of the number of days in their cycle. The mid-way point is usually the best time for ovulation and offers the best chance for pregnancy. It has been defined as 14 days from the first day based on the 28-day average cycle, but these numbers vary from person to person.