Home > Health & Wellness > Health Library > Interactive Tool: When Are You Most Fertile?
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.
Fritz MA, Speroff L (2011). Clinical Gynecologic Endocrinology and Infertility, 8th ed., Philadelphia: Lippincott Williams and Wilkins.
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.
For more information, see the topics Fertility Awareness, Pregnancy, and Fertility Problems. If you are looking for information on birth control, see the topic Birth Control.
Current as of:
November 22, 2021
Author: Healthwise StaffMedical Review: Adam Husney MD - Family MedicineKathleen Romito MD - Family MedicineKirtly Jones MD - Obstetrics and Gynecology
Current as of: November 22, 2021
Author: Healthwise Staff
Medical Review:Adam Husney MD - Family Medicine & Kathleen Romito MD - Family Medicine & Kirtly Jones MD - Obstetrics and Gynecology
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