If you are experiencing a medical emergency please dial 911 immediately
This interactive tool estimates your peak fertility period, also known as your "fertile window." This is when you are most likely to get pregnant. Do not use this tool to prevent pregnancy.
In the tool, you will enter the typical length of your menstrual cycle, and you will click on the first day of your last menstrual period.
Your "fertile window" is up to 6 days long, once a month. It includes:
If you want to become pregnant, try to have sex every day or every other day from your first fertile day to your last fertile day.
If your periods are irregular, this calculator is not a good way to predict your ovulation dates. Do not use this tool to prevent pregnancy.
Source: Fritz MA, Speroff L (2011). Clinical Gynecologic Endocrinology and Infertility, 8th ed., Philadelphia: Lippincott Williams and Wilkins.
Other Works Consulted
- Fritz MA, Speroff L (2011). Clinical Gynecologic Endocrinology and Infertility, 8th ed., Philadelphia: Lippincott Williams and Wilkins.
|Primary Medical Reviewer||Adam Husney, MD - Family Medicine|
|Specialist Medical Reviewer||Kirtly Jones, MD - Obstetrics and Gynecology|
|Last Revised||May 20, 2013|
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