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Fertile Window: How Long Does Ovulation Last?

Understanding your fertile window is crucial when you’re attempting to conceive. Engaging in intercourse during this period can significantly enhance your probability of achieving pregnancy.

You might know that the best time to have intercourse if you are trying to conceive is when you ovulate. It’s time you are the most fertile during your menstrual cycle. So, if you know how long ovulation lasts, you could use this information to calculate your fertile window and give yourself the best chance to get pregnant.

Well, in this post, we are going to learn just that. We will know how you can predict your fertile window and then plan sexual intercourse to give your body the best chance of getting pregnant.

fertile window Right Time For Sex , When Do You Ovulate ?
Right Time For Sex, When is my fertile window?

How long does ovulation last? 

Ovulation is releasing one mature egg from the ovary during your menstrual cycle. Multiple events precede ovulation, and the actual ovulation process lasts around 24 to 36 hours. The eggs develop inside tiny structures in your ovaries called follicles. During the follicular phase of your menstrual cycle, the pituitary gland releases a hormone called the Follicle Stimulating Hormone or FSH that causes these follicles to grow and develop. As the follicles grow, they release yet another female fertility hormone called oestrogen.

As the oestrogen builds up in your body, it reaches a threshold level that stimulates the pituitary gland to release a hormone called Luteinizing hormone or LH. A sudden increase in Luteinising hormone levels in the blood (also called LH surge) stimulates the follicles to burst open and release the egg.

Once the egg is released, it has about 24 hours to fertilise with sperm. If fertilisation does not happen during this period, the egg disintegrates and is thrown outside the body and the upcoming menses. On the other hand, if the egg is fertilised, then you become pregnant.

Understanding your ovarian cycle & fertile window

Your fertile window includes the five days preceding your ovulation and the day of ovulation itself. So, if you know when you are ovulating, it can be easy to calculate the fertile window. You can check your ovulation status with Fertility2Family’s ovulation predictor kit. It is a simple and easy-to-use kit that can detect the LH surge in your body and help you predict when you are ovulating.

As mentioned before, the egg, once released, is active and viable for only about 24 hours. But that does not mean your fertile window is just 24 hours long. The fertile window is much longer than that. Sperm can remain viable within the female reproductive system for up to five days. Therefore, engaging in intercourse in the five days leading up to ovulation also presents a substantial opportunity for successful conception.

Methods to track your ovulation

One of the methods to track your ovulation and predict a fertile window is called the calendar method. In this method, you follow your menstrual cycle for six cycles (six months). The first day of the fertile window is calculated by subtracting 18 from the shortest menstrual cycle you have on record during this period. Similarly, the last day in your fertile window is calculated by subtracting 11 from the longest cycle on record during these six months.

Although it sounds pretty easy to track your menstrual cycle by the calendar method, the results from this method are not entirely reliable. The method assumes that ovulation occurs right in the middle of the cycle, which is not always true. In some women, ovulation can happen between day 6 to day 21 of their cycles. Furthermore, not every menstrual cycle is the same for any woman; changes can lead to miscalculations.

Watching your fertility hormones, especially the Luteinising hormone, is one of the best methods to track your ovulation and predict your fertile window. There is a Luteinising hormone surge 24-36 hours before ovulation, and the peak concentrations are found at 10-12 hours before ovulation. Estrogen levels also increase in the three to five days leading to ovulation.

As ovulation results from the changes in the levels of these hormones, their levels are a better measure to understand when you are ovulating. You are the most fertile when your estrogen rises, and your peak fertility is when the Luteinising hormone reaches its peak.

Chances of conception

Fertility2Family’s ovulation predictor kits can detect the increased Luteinizing hormone levels and help you predict your ovulation. Your chance of conceiving is at its peak the day right before ovulation. Here is a run-down of your chances of getting pregnant during your six-day fertile window.

  • Five days before ovulation: 0.4-7%
  • Four days before ovulation: 8-17%
  • Three days before ovulation: 8-23%
  • Two days before ovulation: 13-29%
  • One day before ovulation: 21-34%
  • Day of ovulation: 8-33%
  • One day after ovulation: 0.8-11%
cervix and preconception
What happens to your body when you ovulate?

Signs of ovulation & your fertile window

Many subtle changes occur in your body during the time of ovulation. Noticing these changes can help you predict your ovulation date and fertile window.

Changes in cervical mucus

Your cervical mucus’s nature, colour, and consistency can tell you a lot about your menstrual cycle. Before ovulation, the cervical mucus is generally thick, creamy, and white or off-white throughout the early phases of your menstrual cycle. When you are ovulating, there is a shift in the consistency and appearance of cervical mucus; it becomes clear and slippery and attains the thickness of an uncooked egg white. Observing your cervical mucus and tracking it for its consistency, appearance, and texture can help you predict your ovulation.

Changes in Basal Body Temperature 

Your basal body temperatures show a small fall just before your ovaries release an egg. Once the egg is released, the basal body temperature increases throughout your menstrual cycle. Before you ovulate, your basal body temperature hovers between 36.1°C and 36.4°C. After about 24 hours post-ovulation, it rises to between 36.4°C and 37°C. Recording your basal body temperature with Fertility2family’s basal body thermometer is a great way to chart your basal body temperature and predict your fertile window.

Changes in the position of the cervix

When you ovulate, there is a change in the position of your cervix. The cervix goes higher and becomes softer during ovulation than during the rest of the cycle. The opening of the cervix also widens during ovulation to receive sperm. If you are comfortable examining your cervix, you can use your fingers to check the status of your cervix and chart it over your entire menstrual cycle.

Signs that your ovulation & fertile window is over

Your fertility returns to normal after ovulation, and you are less likely to conceive. It’s essential to consider both the signs you are about to ovulate and that ovulation has ended if you are trying to time sex with your fertile window to get pregnant.

Changes in cervical mucus

Your cervical mucus becomes a slippery, egg-white consistency during ovulation. Your cervical mucus will revert to its natural texture after ovulation: a dense, creamy, white, or off-white discharge.

Changes in the Basal Body Temperature (BBT)

When ovulating, your basal body temperature can rise by up to 0.5 degrees C. When the marginally higher temperature stays constant for three days or more, ovulation has most likely happened. The basal body temperature remains elevated through the second half of the menstrual cycle. Using a basal thermometer to take your temperature each morning before getting out of bed and charting it will give you further hints that your fertile window has passed.

Changes in the position of the cervix

During ovulation, the cervix is high, soft to the touch, and you can feel an opening, allowing sperm to enter and help you become pregnant. The cervix will return to its original location after ovulation: low, hard to touch, and closed. The cervix can feel like the tip of your nose when you touch it during this period. Decide whether your fertile window has closed by softly feeling for shifts in your cervix, and record it for future reference.

What is a Fertile Window?

The six most fertile days of the menstrual cycle are your fertile window. Those are the only days when you are going to get pregnant as a result of sexual activity. Outside the fertile window, the odds of conceiving aren’t zero, but they are slim. You won’t want to waste your fertile time if you want to get pregnant!

The fertile window refers to the days leading up to ovulation and the days after ovulation. It usually refers to the four to five days before ovulation and the 24 hours after ovulation. The egg is expelled from the ovary and flows down the fallopian tube during ovulation. The egg can be fertilised if sperm travels into the fallopian tube and you become pregnant.

Your eggs are only good for a few hours, 12-24 hours, to be precise. As a result, sperm must come into contact with the egg before the egg becomes inactive. That is why, after ovulation, there usually is only one fertile day. The good news is that sperm will survive in a woman’s cervical mucus for up to five days if the mucus is of high quality. This is why the fertile window covers all the days leading up to and after ovulation.

Luteal Phase
Image courtesy of The Bright Girl Guide by Demi Spaccavento.

Calculating Your Fertile Window: When Are You Most Fertile?

You are not equally likely to conceive on any day of the fertile window. The days leading up to ovulation and the day of ovulation are the most fertile for you. Your highest fertility period lasts two days.

On these two days, the Luteinising hormone also spikes. This hormone spike can be measured using Ovulation Predictor Kits (OPKs) from Fertility2Family. Because menstrual cycles differ from month to month and from woman to woman, an OPK may sometimes produce a false-positive or false-negative test. False positives are extremely rare as ovulation tests are designed to detect the Luteinising hormone in your urine and only produce a second test line if you have LH. Conversely, negative ovulation tests are far more common for multiple reasons. We have discussed this in detail in our 5 Potential Causes for Negative Ovulation Test.

If you find a significant difference in your cycles, you can see a fertility doctor since erratic cycles may signify reproductive problems.

The calendar method

A calendar system involves counting backward from your shortest and longest time to determine your fertile window. The calendar system might not be reliable except for women who have daily periods. It’s possible that our cycles won’t all be the same duration, and we won’t all ovulate 14 days into our next cycle. It’s no wonder obtaining a reliable forecast using the calendar system usually requires six months or more of continuous logging.

Basal Body Temperature (BBT)

After ovulation, the Basal Body thermometer shows a 0.50c temperature rise. Measuring Basal Body Temperature is convenient and easy using Fertiliity2family’s Basal Body thermometer.

Cervical mucus

Throughout the menstrual period, the colour and consistency of the cervical mucus shift. It becomes clear and stretchy around ovulation, resembling an egg white. Keeping track of your cervical mucus is a perfect way to become more aware of your body. It is non-invasive and easy to do once you get the hang of it. However, since everyone’s cervical mucus is different, it may take three to six months of tracking to thoroughly appreciate the specific changes in your cervical mucus that indicate ovulation.

At Fertility2Family, we understand the importance of knowledge and preparation in conceiving. Our extensive blog offers invaluable insights into understanding your fertile window and the intricacies of ovulation, both crucial elements in increasing your chances of conception. To further support your journey, we offer a range of products, including ovulation predictor kits and fertility kits, designed to provide accurate and easy-to-use solutions for tracking your ovulation. We are here to guide and support you every step to parenthood.

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Evan Kurzyp

Evan is the founder of Fertility2Family and is passionate about fertility education & providing affordable products to help people in their fertility journey. Evan is a qualified Registered Nurse and has expertise in guiding & managing patients through their fertility journeys.

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