WellSpan Home

Interactive Tool: When Are You Most Fertile?

What does this tool help you learn?

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.

  • To know how long your cycles are, track the number of days on a calendar for 2 or 3 months or cycles. Your menstrual cycle begins with the day your period starts and ends the day before your next period starts.
  • If you do not know the number of days in your menstrual cycle, you can use 28 days. This is the average length of a menstrual cycle. But if your cycle is longer or shorter than that, or if it is not always the same length, this tool will not predict your fertile window very well.

Fritz MA, Speroff L (2011). Clinical Gynecologic Endocrinology and Infertility, 8th ed., Philadelphia: Lippincott Williams and Wilkins.

What do the results tell you?

Your "fertile window" is up to 6 days long, once a month. It includes:

  • The day you ovulate. This is when you have the best chance of becoming pregnant. (A human egg usually lives for only 12 to 24 hours after ovulation. This is why you are not likely to get pregnant by having sex a day after you ovulate.)
  • The 5 days before ovulation. This is because sperm can live in a woman's body for 3 to 5 days after sex. When an egg is released, one of these sperm is ready to fertilize it.

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.

What's next?

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.

References

Other Works Consulted

  • Fritz MA, Speroff L (2011). Clinical Gynecologic Endocrinology and Infertility, 8th ed., Philadelphia: Lippincott Williams and Wilkins.

Credits

ByHealthwise Staff
Primary Medical ReviewerAdam Husney, MD - Family Medicine
Kathleen Romito, MD - Family Medicine
Kirtly Jones, MD - Obstetrics and Gynecology, Reproductive Endocrinology

Current as ofNovember 21, 2017


Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.

×

Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to https://my.wellspan.org, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.

×