Here’s How To Predict Your Most Fertile Days
When you’re TTC, it can be hard to know when you’re ovulating, and that means it’s hard to optimize your fertility and increase your chances of getting pregnant each month - not ideal!
So, how can you tell when you’re ovulating? And what are the best ways to track your most fertile days? Let’s talk…
When am I most fertile?
There are only a limited number of days during your menstrual cycle when you are most fertile and can become pregnant. These are the few days before and the day of ovulation. Knowing where you are in your menstrual cycle is essential if you want to know how to get pregnant. There are various ways to predict when you will be most fertile to have the best possible chance of conceiving (more on this below!).
What are the main signs of ovulation?
Ovulation is the process of when the egg is released from the ovary. After it is released, it moves to the fallopian tube, where it stays for around 24 hours and waits for the sperm.
The most common signs of ovulation are:
Luteinizing hormone (LH) increases a few days before ovulation which causes the egg to be released - this usually happens 24-36 hours before ovulation
Body temperature rising (see number 3 below for more info)
Sharp pain on one side - also called Mittelschmerz
Changes in saliva due to the amount of estrogen
Changes in cervical mucus to be clear and stretchy (see number 4 below for more info)
Some women don’t experience ovulation symptoms, but it depends on your cycle.
What are some of the ways to track ovulation?
1. Ovulation predictor kits
An ovulation test predicts ovulation and can identify up to six fertile days in each menstrual cycle. They detect the critical fertility hormones during each cycle using a urine sample. They have a 99% accuracy rate, showing the LH increase and when you are most likely to get pregnant. You can find an ovulation test kit at your nearest supermarket or pharmacy.
2. Ovulation calendar method
If you have a regular menstrual cycle, you can predict your most fertile days using an ovulation calculator or calendar by recording the length of each cycle. You should start doing this 3 - 6 months in advance of TTC to see if your periods are consistent.
Ovulation typically happens 12-16 days before your next period if you have a 28-day cycle, with the most likely to be at 14 days. The ovulation days around your cycle are also called the ‘fertile window’ because you are most likely to conceive then.
Even if your cycle is regular, the day of ovulation can vary month to month with each cycle and is inconsistent. Ovulation can be impacted by various factors such as illness, stress, hormonal imbalances, medicine, and daily routines. So, it’s important to mention that the calendar method is not the best ovulation predictor.
The examples below demonstrate how to calculate your most fertile days for regular and irregular cycles:
For a shorter cycle of 21 days, you will most likely ovulate on day 7, which means that days 2-8 are your most fertile days.
For a regular cycle of 28 days, you will most likely ovulate on day 14, which means that days 9-15 are your most fertile days.
For a longer cycle of 33 days, you will most likely ovulate on day 19, meaning days 14-20 are your most fertile days.
3. Basal body temperature recordings
Your basal body temperature (BBT) rises 0.4-1.0°C or 32.7-33.8°F after ovulation. To build an accurate picture of your BBT leading up to ovulation, you should measure your BBT first thing in the morning for several months before seeing consistent patterns. Many factors affect your BBT; some studies have shown that using BBT as a way to predict ovulation is less than 70% successful.
4. Cervical mucus observations
During your menstrual cycles, your cervical mucus changes. At the time of ovulation, your cervical mucus will be thin, clear, and stretchy, resembling an egg white. After ovulation, mucus usually becomes thicker and gradually dries until your fertile period is over. By keeping track of your cervical mucus changes, you can predict when you will be at your most fertile. It’s a great way to get to know your body and how it changes with the cycle, but like other methods, it may not be the most accurate predictor and can take some time to notice patterns.
What are the key takeaways?
There are many ways to calculate and predict your most fertile time. Although the methods for predicting ovulation are simple, fertile days are not always easy to pinpoint and are never 100% accurate. To maximize the chances of getting pregnant, when preparing for pregnancy, you should have unprotected sex 2-3 days leading up to, and including the day of, ovulation. It can increase the chance of pregnancy by 20 - 30%, but it also depends on your age. If in doubt, a doctor can assess your overall health and then decide on the best possible strategies for you.
This post was written with My Expert Midwife and has been signed off by a qualified midwife.
About the author: My Expert Midwife creates clinically approved pregnancy products for women, men, and babies developed by a team of expert midwives. They also provide advice helping to support parents through their pregnancy journey and beyond.
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