What Does “Fertile Window” Mean?

The fertile window is the six days in your menstrual cycle when you’re most likely to get pregnant -- the day of ovulation and the five previous days. Tracking your fertility can be a complex task.

Contrary to the fear-mongering tactics of your school’s sex-ed classes, having sex doesn’t automatically mean you will get pregnant.

Far from it, in fact.

Getting pregnant can actually be a pretty tough job, even if there are no fertility issues to take into account.

In reality, there is only a short amount of time each month when a woman is able to get pregnant, and this small window of opportunity can also be known as, you guessed it, the fertile window.

So what is the difference between ‘fertile’ and ovulation?

What does being fertile mean?

And how can you tell if you are?

Here’s everything you need to know about this short-lived baby-making opportunity.

In this article: 📝

So, what does “fertile window” mean?

As we’ve said, the fertile window is the period of time each month when a woman can become pregnant.

The fertile window is six days long, which accounts for the maximum of five days sperm can survive inside the fallopian tube, plus the one day for the woman to ovulate.

Although the fertile window is six days long, the chances of getting pregnant dramatically increase in the two days leading up to ovulation plus the day of ovulation.

What is the difference between ovulation and fertile days?

Rather than a window of time, ovulation is one single occurrence that happens on one day, when the levels of a particular hormone in your body trigger the release of a mature egg into your fallopian tube.

Within 12-24 hours after ovulation, the egg, if not fertilized, will no longer be viable for pregnancy and instead will initiate your next period.

The trick is for the sperm to already be in the fallopian tubes when the egg is released.

Sperm can survive inside the fallopian tubes for two to five days, and this is why having sex in the days leading up to ovulation often provides the best chance of conceiving.

Your most fertile days are the two days leading up to ovulation and the day of ovulation.

How do I know my fertile window?

To work out your fertile window, you can start by tracking your menstrual cycle length.

On average, women ovulate around 14 days before their period begins, and the average menstrual cycle is around 28 days (though it can vary from 24 to 35 days).

So, let’s do some math.

Say after a few months of tracking your periods you calculate that your average cycle lasts 29 days.

That means you probably ovulate on day 15.

So your fertile window will be days nine to 15, with your most fertile days being days 13, 14, and 15.

How do irregular periods affect your fertile window?

If your menstrual cycles don’t seem to follow a regular pattern, you may need more help than math and a calendar to figure out your fertile window.

You can use ovulation tests to track the hormone levels in your urine to best indicate when ovulation is about to occur.

Irregular periods can make conception difficult, so some couples who are trying to get pregnant will have sex every two to three days all cycle long to maximize their chances of conceiving.

What happens when you are fertile?

When you are most fertile, the chances of becoming pregnant go from 0% to around 30%.

If you are purposely tracking your cycle to become pregnant, you may also notice some physiological changes to indicate you are most fertile:

• The amount of vaginal mucus increases and becomes clear, stretchy, and slippery, almost like raw egg-white. You might notice it in your underwear or on toilet paper when you wipe after using the bathroom. This is the ideal kind of vaginal mucus to keep the sperm alive and help them swim to the fallopian tubes.
• Your basal body temperature dips in the day or two before ovulation and spikes just after. You can track this with a basal body thermometer, specifically, just before getting out of bed every morning.

What does fertile mean on my period tracker?

If you’re using a period tracker which indicates you are fertile, it means you are within your fertile window and ovulation is imminent.

If you’re trying to get pregnant, it’s go time!

Stop reading this and get your partner into bed!