How to Determine Your Fertility Window

Posted by Nicole on June 25

Having a difficult time conceiving? While there are a number of ways you can strive to boost your fertility, one thing which can improve your chances of getting pregnant is to have sex during your fertility window. This is the phase of your menstrual cycle during which your fertility is at its peak. In this article, you will learn how to determine when that window is open each month.

What is the Most Fertile Part of Your Cycle?

You are at your most fertile in the days just before you ovulate. As this resource explains, “Pregnancy is technically only possible if you have sex during the five days before ovulation or on the day of ovulation. But 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.”

How Do You Know When You Have Reached Your Window?

If you have regular menstrual cycles, you can run a simple calculation to figure out when you are at your most fertile:

1. First, figure out how long your menstrual cycles are. The day your bleeding starts during your period is Day 1. Count the days until your next period. This tells you the full length of your cycle.

2. The length of a luteal phase (the phase following ovulation) can range anywhere from around 11 to 17 days, with the average being about 14. So subtract 14 from the number of days in your menstrual cycle. This gives you the approximate day that you ovulate.

If you have irregular menstrual cycles which vary in length, it can be harder to figure out when you will reach your fertility window each time.

Here are a couple of methods which can help:

  • Be on the lookout for signs of ovulation each cycle. A good example is the thickening of cervical mucus. A rise in basal body temperature is another. If you track these things consistently and take notes, you’ll get a better feel for your cycles, and may spot some patterns in the timing, even if your cycles are not totally consistent.
  • Try using an ovulation kit or a fertility monitor. The American Pregnancy Association says, “When taken correctly, ovulation tests are approximately 99% accurate in detecting the LH surge that precedes ovulation.” Usually, ovulation will occur a day or two later. So if the kit detects a surge, you are probably in your fertility window.

It may take months of effort before you really get good at predicting when you will ovulate (even knowing when to start using an ovulation kit can be a challenge). But your patience will be rewarded if you stick with it and do not give up.

Still Need More Help?

If you are still not conceiving, it is a smart idea to make an appointment with your healthcare provider for some professional advice. You also might consider taking an herbal supplement to support your reproductive health. Good luck!