My average menstrual cycle length is not correct. Why? And how can I fix?
MyMonthlyCycles automatically calculates your average menstrual cycle length based on your menstrual cycle tracking history. More specifically, it's based on the first day of each menstrual period that you track.
Your average menstrual cycle length is shown and used in several places in MyMonthlyCycles, including:
Shown on our menstrual calendar and period calendar, on the Cycle Dashboard.
Shown on My Cycle History >> Summary View.
Shown on and used on MyMonthlyCycles Menstrual Calculator and Ovulation Calculator; Also used on many reminders, and more!
Below we outline the most common issues why average menstrual cycle length (acl) is incorrect, and how to identify where the problem(s) are. Solutions for resovling, whether due to data entry error or cycle activity, are located at the end of this section.
But first, definitions: Menstrual cycle length is the number of days from the first day of your period up to and including the day before your next period starts. Quick Example: Period starts Jan 1. Next period starts Jan 27. That cycle's length is 26 days.Average cycle length (acl) is the average of all the cycles* you've tracked in MyMonthlyCycles. Because all of your cycles factor into your acl, if you have one or more cycle that is significantly longer or shorter than usual, it can affect your acl.
*If you setup exclusion rules on My Preferences, cycles that satisfy your exclusion rules are not included when average cycle length is calculated.
Reasons ACL may be Incorrect:
If your acl is longer than it should be, you likely didn't track several periods, and that large gap of several months (or years!) is causing the problem.
Example: you tracked your periods for March, April, and May 2023. Then the next period you tracked was in November 2023 onward. The "cycle" bewtween your May and October period would be taken into account when calculating your acl, thereby causing the problem.
Recording your last period before pregnancy and then the next period following pregnancy can also cause problems with your acl.
You may have had one or more irregular cycles that were longer than your usual length.
If your acl is shorter than it should be, you may have tracked some periods by tracking just the first and last day of your period. Because MyMonthlyCycles auto-detects the first day of your period, MyMonthlyCycles will assume your last day is actually a new period, and this causes short cycles to be factored into your acl.
Example: Your last period started October 9 and went til October 12 . You entered a period event record for October 9th and then again for October 12th. You didn't enter a period event for October 10th or 11th. MyMonthlyCycles assumed that October 12th was a new period and therefore a new cycle. The previous "cycle" (Oct 9-11) was just 3 days. It will most definitely cause acl to be wrong.
Another reason is that you may have had one or more irregular menstrual cycles that were shorter than your usual cycle length.
Average Menstrual Cycle Length can only be calculated if you have put in at least the first day of 2 menstrual periods. If you've only tracked 2 periods, acl is actually just that 1 cycle's length as there's not enough information to create an average. If you've only tracked 1 period, there's not enough information to calculate acl. Your average cycle can not be calculated if all of your menstrual cycles are excluded due to your min/max exclusion rules (on My Preferences).
Identifying the ACL problem:
If the problem is due to data entry, you need to identify where your menstrual cycle tracking went astray. There are several ways to do so:
Run the Menstrual Cycle Chart & Report on the MyMonthlyCharts menu, which provides a very detailed report of all your cycles and will easily show which cycles are causing the problems.
You can also use the My History report, and select just the Period Event. If doing so, we recommend you run the chart view, and select the last 3 years.
You can use the Period Tracker Calendar. Switch to 12 month view so you can see many menstrual cycles at once. Note the cycle day count, which will enable you to easily see the length of each menstrual cycle.
On either the Period Calendar or the menstrual calendar, make note of the Cycle Day, particularly the cycle day number on the day before the first day of any period. That tells you the cycle's length, so if it doesn't look right to you, look at the adjacent periods.
Solutions to correct ACL:
If the acl inaccuracy is due to cycle activity such as occasional irregularity or pregnancy, you can use Exclusion Rules on the My Preferences screen to exclude cycles that are longer or shorter than usual from your Average Cycle Length calculation.
If you recorded the last period before you were pregnant, and then your next period after your baby was born, you should use the exclusion rule "Exclude menstrual cycles that are greater than {you fill in} days". You'll want to select a value that's greater than your usual cycle length. So, if your cycle is generally 25-29 days, you might select 35 or 40. That will not only exclude from your acl the time when you were pregnant, but if you occasionally have a longer than usual cycle.
If you were pregnant but had a miscarriage, you can also use exclusion rules, as outlined just above, to adjust your acl.
If acl is wrong because you have several months where you skipped tracking your periods, either track those periods in MyMonthlyCycles, or remove the earlier period prior to the gap. If you prefer to keep those periods, then you need to use Exclusion Rules on the My Preferences page.
If you tracked some periods by adding the first and last day of some periods, you need to fix this by either tracking just the first day of your period, or by filling in all days of your period. You can do this easily on MyMonthlyCycles Period Tracker Calendar.
For complete details, refer to Can I track just the first day and last day of my period?, (quick answer - No!). Please click to that document, where you'll find lots of details and examples!
Disclaimer: All information provided is for educational purposes only. It is not intended as a substitute for advice provided by a medical doctor or qualified healthcare provider. You should not use this information for self-diagnosis or for treating a health problem or disease. If you have any questions whatsoever about your medical health or believe you have a medical problem or disease, you should contact your medical doctor or healthcare provider. You should never disregard medical advice or delay seeking medical advice or treatment because of something you have read in this glossary. No guarantee is made about the accuracy, completeness, or relevance of the information contained herein.
