The fertile window is the period during a woman's menstrual cycle when pregnancy is possible. It includes the day of ovulation (when an egg is released from the ovary) and the five days beforehand. Having intercourse during this time gives you the highest chance of conceiving.
Find Your Most Fertile Days
Pinpoint your ovulation and fertile window with our easy-to-use estimator and interactive calendar.
Calculate Your Fertile Window Now →How to Calculate Your Fertile Time
Knowing when you're ovulating is key to maximizing your chances of pregnancy. Here are several methods to estimate your fertile window:
- Menstrual Cycle Tracking: If you have a regular menstrual cycle, ovulation typically occurs about 14 days before your next period. However, cycles vary in length, so tracking is essential. A menstrual cycle calendar can be helpful.
- Basal Body Temperature (BBT) Charting: Your basal body temperature rises slightly after ovulation. Tracking your daily temperature can help you identify this pattern.
- Ovulation Predictor Kits (OPKs): These kits detect the luteinizing hormone (LH) surge, which precedes ovulation by 24-36 hours.
- Cervical Mucus Changes: During ovulation, cervical mucus becomes clear, slippery, and stretchy, resembling raw egg whites.
While these methods offer valuable insights, they aren't foolproof. For more precise fertility tracking, consider using a comprehensive tool like our Pregnancy Calculator & Ovulation Estimator.
Facts About Timing
- Pregnancy is technically only possible if you have sex during the five days before ovulation or on the day of ovulation.
- The most fertile days are the three days leading up to and including ovulation. Having sex during this time gives you the best chance of getting pregnant.
- By 12-24 hours after ovulation, a woman is no longer able to get pregnant during that menstrual cycle because the egg is no longer in the fallopian tube.
Remember, sperm can live for around five days, while an egg can only be fertilized for around 24 hours (one day) after being released from the ovary. Thus, timing is crucial.
What If I Have Irregular Periods?
If you have irregular periods, meaning that your periods are outside of the 21–35-day window, it can be more challenging to pinpoint your fertile window. In such cases, consulting with a healthcare provider or fertility specialist is recommended. Our ovulation estimator can still provide a personalized timeline to help you plan for conception.
Busting Myths
Myth: A woman can get pregnant any time of the month.
Fact: A woman can only get pregnant on a few days during her menstrual cycle.
Why? Because eggs and sperm only live for a short time and need to come together at the right time for fertilization to happen to create an embryo.
Improve Your Chances of Pregnancy
To increase your chances of pregnancy, consider the following:
- Have sex as close as possible to the time of ovulation.
- If a woman has sex six or more days before she ovulates, the chance she will get pregnant is virtually zero.
- If she has sex five days before she ovulates, her probability of pregnancy is about 10 percent.
- If she has sex on the day of ovulation, or the two days before, the chance of getting pregnant is around 30 percent.
These are average figures and depend on a woman’s age.
How Our Tool Can Help
Our Pregnancy Calculator & Ovulation Estimator can help you work out your most fertile time. It can also estimate your due date if you do become pregnant during your next fertile days. This tool provides personalized timelines and predictions to help you navigate your pregnancy or plan for conception.