When is a woman most fertile?

It's a persistent misconception that a woman is equally fertile at all times of her cycle. This is far from the truth. On average, a woman is only fertile for a few days per cycle.

So why are there so many types of contraception on the market, offering constant protection against pregnancy, even though you're only fertile for a few days per cycle? It's difficult to accurately predict these fertile days. Sperm survival also plays a role.

If pinpointing your fertile days were easy, you'd know exactly which days are more or less likely to conceive. This is a bit complicated to figure out, but not impossible. A woman is always fertile around ovulation, not at other times of the cycle. And there are several ways to determine your most fertile period.

Note: This article will focus on determining fertility as a way to conceive, rather than as a way to avoid pregnancy. These natural methods of measuring fertility are not recognized as safe contraceptives.

A menstrual cycle, also known as a hormonal cycle, lasts an average of 28 days. In short, the hormonal cycle consists of four phases.

The four phases of the hormonal cycle:

• Menstruation - This is the period of bleeding. A new cycle begins, during which follicles grow toward ovulation.
• Pre-ovulation - Follicles containing an egg cell continue to develop.
• Ovulation - One follicle develops fully and ovulation occurs.
• Premenstruation - The body prepares for pregnancy after ovulation.

Ovulation occurs on average on day 14. You're fertile just before and after, but not on the other days. The released egg is fertile for an average of 24 hours after ovulation[ 1 ]. So how is it that you have a longer chance of pregnancy?

So an egg is only truly fertile for one day. How is it then that the chance of pregnancy lasts for many more days? This is due to the survival of sperm cells. These are fertile for an average of about two days, but in exceptional cases, they can be found alive for up to eight days after intercourse[ 2 ].

This suddenly increases the number of days when there's a chance of pregnancy! So, if you had unprotected sex a few days before ovulation, you could get pregnant.

However, the chance is greatest from two days before ovulation to one day after. That's when you're most fertile.

You now know that you're most fertile two days before and one day after ovulation. But how do you know when you're ovulating? There are several methods for this.

Based on your previous cycles, you can calculate the following. It's actually quite simple: when you get your period, you're on day 1. Your next ovulation would then occur on day 14. However, this isn't very reliable. A cycle can be shorter or longer due to stress, changes, and other circumstances. As a result, ovulation can occur earlier or later than expected.

An ovulation test measures the amount of LH in the urine. This is the hormone that rises in the days before ovulation. A positive LH test means you know ovulation will occur within one or two days.

The test works like a pregnancy test, often in the form of a strip. You take the test by collecting a sample of urine with the strip. Lines then appear, indicating whether or not ovulation is imminent.

Both popular and notorious these days: measuring body temperature to determine your fertility. Whether it's reliable or not, if you have a regular cycle, taking your temperature can provide significant insight into your cycle.

In short, the temperature drops around menstruation and rises again after ovulation. This difference can be as much as a whole degree! This results in interesting graphs. So it's certainly not a guessing game, but highly recommended for any woman trying to conceive.

Cervical mucus changes during your fertile period. While it's whiter and thicker at other times of the cycle, fertile cervical mucus is recognizable by its clear, transparent, and elastic texture.

While this isn't the case for everyone, ovulation comes with various physical symptoms. You can keep a diary to track when you feel which symptoms, giving you more insight into your fertile days.

Symptoms of ovulation:

• Cramps similar to menstrual cramps
• Tender breasts
• Higher body temperature
• Retain moisture
• More desire for sex

There are also things you can do yourself to increase your fertility. These are lifestyle adjustments that make your body healthier overall[ 3 ].

• Stop drinking alcohol
• Quit smoking
• Healthy and varied food
• Drink enough water
• Get enough sleep
• Reduce stress

After you stop taking the pill, it can take a while for your fertility to return. This is because your hormone cycle needs to get back on track. So, if you've just stopped taking the pill, give your body some rest and don't worry if it takes a little longer for your period to return or for you to get pregnant.

When a couple wants to conceive, it's also important to consider the man's fertility. For example, read this article with 19 ways to improve sperm quality.