How to Calculate How Many Days Between Periods

Calculate how many days between periods to learn your menstrual cycle.

Hormone fluctuation is the power behind everything that occurs during the monthly menstrual cycle. Learning the pattern of a woman's menstrual cycle is important information that many women strive to understand. Whether a woman is actively trying to conceive a pregnancy or avoid a pregnancy, the menstrual cycle provides clues that can help determine fertile times. Calculate how many days between periods to understand your individual cycle. You can then take this information and use it to achieve pregnancy, prevent pregnancy or just manage your life.

Things You'll Need

• Calendar

Instructions

1. Make a mark on the calendar on the day your menstrual cycle begins (the first day of bleeding).

2. Make a mark on your calendar on the day your next menstrual cycle begins (the first day of bleeding).

3. Count the number of days between the two marks (including the first mark but not including the second mark). This is the number of days that just occurred during your most recent menstrual cycle.

4. Track the days in your menstrual cycle for 6 months. After this time elapses, compare the number of days in each cycle to see if your cycles are regular. If each cycle contains roughly the same number of days, you have a useful pattern that will help you know the length of your menstrual cycle. According to the NetWellness website, variations of two to three days is normal.

References

• NetWellness: The Menstrual Cycle and Ovulation