Ovulation Calculator FAQ
How do I Use MyMonthlyCycles Ovulation Calculator
Use the ovulation calculator criteria page to enter your cycle information which is then used for predicting your ovulation dates and fertile days.
If you are a MyMonthlyCycles member and are logged in, on entry to this criteria page, some of the fields below may be filled in based on your menstrual cycle tracking data. This will be described in more detail below for each field. Note that you can change any field that is pre-populated based on your cycle tracking history. This can be useful if you want to simulate what-if scenarios.
If you are not a MyMonthlyCycles member, or are not logged in, some of the fields will contain default values. You can change any such field, as necessary, to properly reflect your fertility cycle data. Note: If you are a member, but not logged in, and would like to make use of your tracking history, simply log in and then return to the ovulation calculator.
Note - Members: If you want the ovulation calculator to use your tracking history information, you should keep your period tracking history up-to-date. In particular, you should make sure to track your period each time you get it, so that your average menstrual cycle length can be accurately calculated. And, it's important that the first day of your last period is entered into MyMonthlyCycles, since the next (and subsequent) ovulation dates are predicted based on the first day of your last period. Of course, as noted above, while you can change any value pre-populated on the ovulation calculator criteria screen, keeping your menstrual history current facilitates using the ovulation calculator.
Step 1. Ovulation Calculation Rule
The ovulation calculator needs to know the date of your last period, your average menstrual cycle length, and your luteal phase length, all defined below. For information on how these fields are used by the ovulation calculator, click on the link How the Ovulation Calculator Works, available on the criteria/results pages.
First day of your last menstrual period: Use the drop-down boxes to specify the first day of your last period.
If you are a logged-in member, on first entry to this screen, this field will automatically be filled in with the first day of your last period, as stored in MyMonthlyCycles. If you've not yet entered tracking history, or if you have not yet posted your last menstrual period date, you can enter or override the value displayed here.
Your average menstrual cycle length: Specify the average number of days in your menstrual cycle.
If you are not a member, or are not logged in, the default is 28 days; however, if your average cycle length differs from this, make sure to select the appropriate value.
If you are a logged-in member, and you have posted sufficient cycle information in MyMonthlyCycles (at least two adjacent menstrual periods), your average cycle length will be automatically calculated and filled into this field on entry to this screen. Your average cycle length is calculated as is done in other areas of MyMonthlyCycles: if you have specified Cycle Exclusion Rules on the My Preferences screen, they are taken into account during the calculation. Consequently, if all cycles are excluded, such that the average cycle length can not be calculated, the default of 28 days will display in this field; Moreover, if the calculated average cycle is outside the valid range for cycle length used by this ovulation calculator (see below), the default of 28 days will display. For further information on how your average cycle length is calculated, you can use Quick History (on the My History screen). If your average cycle length is filled in, you can override it, if necessary.
Note that the valid menstrual cycle length range for this ovulation calculator is between 22 and 45 days. The ovulation calculator cannot be used with cycle lengths outside this range.
Use the drop-down box on the ovulation calculator criteria page to specify your luteal phase length, if different than the default of 14 days.
The luteal phase is the third phase of the menstrual cycle, and is the time span occurring after ovulation until the day before your next menstrual period begins. For many women with regular cycles, the luteal phase is generally from 10 to 16 days, with 14 days being the average length.
If you know your luteal phase, for instance because you have charted your fertility cycles in the past or have used ovulation prediction tests, you can override the default by selecting your luteal length from the drop-down.
If you do not know your luteal length, you should leave the default of 14 days. Most ovulation calculators automatically use 14 days.
This is an advanced feature and should be used by those who have already used other means to determine their luteal phase length. It enables you to fine-tune the calculation based on what you've previously learned about your cycle.
Note that the valid luteal phase length range for this ovulation calculator is between 10 and 16 days. The ovulation calculator cannot be used with luteal lengths outside this range.
Several MyMonthlyCycles tools can calculate your luteal phase:
Default Luteal Phase Length: You can use Preferences to specify your luteal phase. If set on My Preferences, its value will be displayed by default on tools that utilize luteal phase length.
Step 2. Ovulation Calendar Display Options
Select the display options you want to use when your ovulation calendar is generated:
How Many Ovulation Cycles to Calculate: Select how many future fertility cycles you want predicted. For instance, the Next 3 Cycles, the Next 6 Cycles, etc. For each cycle, the first day of your period will be shown, along with the ovulation date in that cycle and the fertile days surrounding it.
Ovulation Calendar Display Type: Select whether to display your ovulation calendar in calendar format, or in date book format.
Calculate Ovulation Specify your ovulation calculation rules, and display options. Then, click the Calculate button to continue to the next page, where the calculated ovulation calendar will be shown.
Note: If there is a validation error, such as an invalid date, this screen will re-display when you click the Calculate button, with details regarding the problem. If this occurs, the ovulation criteria screen re-displays with the data you've just filled in; In this case, if you are a logged-in member, the initial history data that may have displayed is not filled in again. If you want to start over again, utilizing your menstrual tracking history data as the defaults, simply re-select the ovulation calculator from the menu at left.
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.