Your Fertile Day
When you know your average menstrual cycle length, you can work out when you ovulate. Ovulation happens about 14 days before your period starts. If your average menstrual cycle is 28 days, you ovulate around day 14, and your most fertile days are days 12, 13 and 14.
Rise in basal body temperature, typically 1/2 to 1 degree, measured by a thermometer
Higher levels of luteinizing hormone (LH), measured on a home ovulation kit
Cervical mucus, or vaginal discharge, may appear clearer, thinner, and stretchy, like raw egg whites
Slight pain or cramping in your side
Did you know that tracking your fertile days can increase your chances of getting pregnant? Or even help you figure out which days to avoid having intercourse so that you don’t get pregnant?
Whether you’ve just started your journey of trying to conceive, have been try for a while without success, or aren’t quite ready to start a family, tracking the days you’re most fertile (called fertility awareness) can help. It’s all about getting to know your body and its natural rhythm so that you can better predict when ovulation will occur.
There are many different methods, apps, and devices you can use to tracking your fertility. Some are more effective than others and some work best when used in combination with other methods. We’ve broken down each method for you so that you can determine the best fertility awareness method for you and your body. We’ve also compiled a list of our favorite fertility tracking apps and tools that can make getting pregnant (or not getting pregnant) easier.
What Is Fertility Awareness?
Fertility awareness (also commonly called fertility tracking, ovulation tracking, natural family planning, or fertility charting) is knowing and recognizing when you’ve entered the fertile window of your menstrual cycle. This fertile window includes the five days before your ovaries release an egg each month and the day of ovulation. These are the six days you’re most likely to get pregnant based on the idea that sperm can live in the uterus for up to five days and an egg can survive 12-24 hours after ovulation.
Fertility awareness-based methods (FABMs) are the methods used to naturally track when your body is entering the fertile window. FABMs can be used to predict when you’re most likely to conceive each month or as a natural form of birth control — giving you an indication of which days you should avoid sexual intercourse or use a barrier method such as a condom.
(It’s important to note that using FABMs as a form of birth control is not as effective in preventing pregnancy as other forms of birth control, such as pills or an IUD.)
What Are the Benefits of Fertility Tracking?
Since there are only six days each month in which you can get pregnant, FABMs can help take the guesswork out of when you will ovulate. Clinical guidelines suggest that your fertile window falls between days 10 and 17 in a typical 28-day menstrual cycle. However, according to a study conducted in 2000, 70% of women ovulated outside of that time frame. The same study also found that for those women who have regular cycles, the day of ovulation was highly unpredictable. To top it off, another study from 2006 found that factors such as stress, diet, and sleep can affect the length of your cycle as well as when you ovulate.
This is where FABMs come in. Your body naturally provides signs about your fertility status throughout your menstrual cycle. When you know what to look for and how to track these signs, you’ll learn to identify your own individual pattern over time.
When used correctly, FABMs are 76-88% accurate in determining your fertile window. Their effectiveness can be further increased when you have the discipline to check and chart your fertility signs each day as well as work with a health care professional who can help you chart them correctly. FABMs are also more effective when you combine multiple methods.
Common Signs of Ovulation
The following are all signs that your body is entering its fertile window. The methods we’ll cover below can help you track and notice these signs to best determine where your fertile windows falls in your monthly cycle.
- Positive result on an ovulation predictor test
- Sustained basal body temperature increase
- Fertile quality cervical mucus
- Fertile saliva ferning pattern – Named for the fern-shaped crystals that form in your saliva during ovulation
- Fertile cervical position
- Mittelschmerz pain (ovulating pain) – Pelvic and lower abdominal pain that some women experience during ovulation
- Increased sexual desire
- Breast tenderness
Fertility Awareness-Based Methods You Can Use to Track Your Fertile Days
Calendar Method (Standard Days Method)
The calendar method, or standard days method, uses the typical length of your menstrual cycle and the date of your last period to predict when you’re most likely to ovulate. This method assumes that a typical menstrual cycle is between 21 and 35 days long and the average luteal phase is 14 days. Your luteal phase is the time between ovulation and the first day of your next period. Like the length of your menstrual cycle, your luteal phase varies and can be anywhere from 10 to 15 days long.
It’s recommended that you track the length of your menstrual cycle for at least six periods to get an accurate representation of your average cycle length. By charting your average cycle length, the length of your luteal phase (if you don’t know it, use 14 days), and the first date of your last period on a paper calendar or using an online calendar or app, you can then predict when your fertile window will most likely fall.
Because this method relies heavily on averages, it’s not always 100% accurate. If you’ve been charting your cycle for a while, your cycle and ovulation date can vary from cycle to cycle, even if you have pretty regular periods. If you’re more irregular, calculate your average cycle length and then give yourself a wider fertility window than the typical six days to account for any inaccuracies in your calendar charting. You can find more information and instructions for using the calendar method here.
Here are a few online ovulation calendars you can try:
Basal Body Temperature Method
Your basal body temperature (BBT) is your internal temperature when you first wake up in the morning. Your BBT changes throughout your menstrual cycle and is typically lower before ovulation (between 96-98° F) and higher after ovulation has occurred (between 97-99° F). This increase in temperature is caused by increased progesterone levels that are associated with ovulation. By taking your temperature each morning before you get out of bed, you can detect shifts in your BBT that may signal ovulation.
Your BBT will remain high for the two weeks following ovulation and then drop again before your next period. When a rise in temperature is sustained for at least three days, it’s a good indication that ovulation has occurred.
It’s recommended that you chart your BBT for at least three months to get an accurate prediction of your fertile window. You can find more in-depth information about BBT measurements in our blog post, “Basal Body Temperature and Ovulation.”
Cervical Mucus Method
Cervical mucus (vaginal discharge) is secreted by glands found in and around your cervix and serves two purposes: 1. to prevent things from entering the uterus through the cervix outside of your fertile window; and 2. to nourish and transport sperm through the cervix and into the uterus during your fertile window.
The cervical mucus method (also called the Billings Ovulation Method®) attempts to track changes in color, texture, and amount of your cervical mucus throughout your menstrual cycle to determine when you’re going to ovulate. In general, drier, stickier cervical mucus typically means less fertile, while wetter, thinner mucus indicates fertility. Around the time of ovulation, your cervical mucus will begin to thin and become clear, much like the consistency of a raw egg white. This allows sperms to pass through the cervix and provides them a more alkaline environment to survive in.
Your cervical mucus will go through the following stages during your menstrual cycle:
- Not ovulating – Mucus is dry or sticky
- Ovulation may be coming – Mucus is creamy
- Ovulation is very close – Mucus is wet and watery
- Ovulation has occurred – Mucus is very wet, stretchy, and resembles raw egg whites
When using this method to determine your fertile window, you should check your mucus every day (except during your period) and record the results on a chart. While this may make you squeamish, remember that it’s natural and your body’s way of helping you get pregnant. It’s best to start using this method with the help of a health care provider as it can be hard to determine the differences in mucus consistency on your own. Keep in mind that medications, feminine hygiene products, douching, sexual intercourse, breastfeeding, or having a pelvic exam in which lubrication is used can all change the look of your cervical mucus.
This method is most accurate when combined with the BBT method. On its own, the Centers for Disease Control and Prevention (CDC) estimates that the cervical mucus method is 97% accurate.
The TwoDay Method®
The Twice a day method is a variation of the cervical mucus method. Using this method, you should check your cervical mucus twice daily and then ask yourself two questions:
- Did you notice any cervical mucus secretions today?
- Did you notice any cervical mucus secretions yesterday?
If the answer to these two questions is “yes,” you’re most likely fertile. If you did not notice secretions two days in a row, you’re most likely outside of your fertile window. Studies have shown that, when used correctly, the TwoDay Method is 96% accurate in determining if you are fertile.
The Symptothermal Method
The Symptothermal Method (STM) is a combination of the BBT, cervical mucus, and calendar methods. When combined, these three methods have an efficacy rate of 99.6%.
The STM is considered to be the most accurate fertility awareness-based methods because each of the three methods relies on different signs to predict your fertile window. This helps you to further narrow down your fertile days and gives you backup methods you can trust if your temperature or cervical mucus are out of whack for a few days due to stress or illness.
Cervical Position Method
The position, firmness, and openness of your cervix change throughout your menstrual cycle. These three characteristics are referred to as your cervical position and can be used to determine if you’re within your fertile window.
At the beginning of your menstrual cycle, your cervix is firmer, closed, and sits lower in your vagina. As you approach ovulation, however, your cervix moves up higher, opens slightly, and become softer to the touch.
By tracking your cervical position, you can get an understanding of when you’re approaching ovulation so that you can prepare accordingly. Learn more about how to check your cervix position here.
Ovulation Predicator Kits
Ovulation predictor kits are considered one of the most accurate methods of predicting ovulation. Similar to home pregnancy urine tests, ovulation test strips measure your luteinizing hormone (LH) levels and show a particular color when these levels surge. LH is responsible for causing your ovaries to release an egg during ovulation, and a surge in LH levels typically indicates that you will ovulate within 12 to 36 hours.
You may have to take the test daily over several days to accurately detect an LH surge. If you use a test strip for five days, the chance of predicting ovulation is 80%. If you test for 10 days, the likelihood jumps to 95%. If a test predicts ovulation, it is recommended that you have sex daily for the next two to three days if you are trying to conceive.
You can buy many different brands of ovulation predictor kits that vary in price. A few of our favorite are the Clearblue® Ovulation Test System, First Response™ Easy Read Ovulation Test, Modern Fertility Ovulation Test, Wondfo One Step Ovulation Test Strips, and the Pregmate® ovulation tests.
Saliva Ferning Tests
Did you know your saliva can also signal ovulation? Chemical changes occur during your fertile window and when dried, fern-like crystals (where the name ferning comes from) appear in your saliva. Saliva ferning kits include a lens that you place a drop of saliva onto. After five minutes, all you have to do is use the provided viewing scope to see if the characteristic fern-like crystals are present.
Apps That Make Fertility Tracking Simple
While tracking all of these ovulation signals may sound overwhelming, there a many different apps and resources out there that make tracking everything a breeze. Your Walnut Hill physician can provide calendar charting tools, or you can use one of the below apps to track multiple FABMs at once.
- Fertility Friend
- Available on iPhone & Android
- Features: Helps you track your period, BBT, cervical mucus, and more. Offers an ovulation calendar, menstrual calendar, fertility chart, and a period tracker.
- Cost: Free or you can pay for the $45/year premium membership, which includes VIP access to message boards and advanced features.
- Natural Cycles
- Available on iPhone & Android
- Features: Includes a fertility calendar, daily health log that allows you to track 40 different health signals, health insights, and the capability to share your data with your partner.
- Cost: Free or you can pay $47.99 for one year of Glow Premium, which include comparative insights, private messaging, the ability to create a custom profile, access to a premium library of articles, and more.
- Available on iPhone & Android
- Features: Chart your period, BBT, cervical mucus, cervical position, sexual intercourse, test results, PMS symptoms, and more. Includes data-driven predictions for fertility and menstruation based on the data you log.
- Cost: Free or you can pay $49.99/year for Kindara Premium, which includes unlimited custom data, tracking options for vaginal sensation and moods, direct messaging and invite-only groups, and more.
- Modern Fertility
- Available on iPhone (Android coming soon)
- Features: Predict the two days you’re most likely to get pregnant by tracking your periods, ovulation test results, and sex life. Includes ability to scan ovulation test results for an instant read on your LH levels.
- Cost: Free
Other Fertility Tracking Gadgets and Tools
In addition to apps, there are other gadgets and tools you can buy to track your fertility signals.
- Ava is a bracelet you wear at night that tracks your skin temperature, heart rate variability ratio, breathing ate, resting pulsing rate, and perfusion. It then detects your five most fertile days as they’re taking place so you can properly time intercourse.
- Cost: You can purchase Ava Basic for $279 or upgrade to Ava Plus or Ava Premium for guaranteed results in six or 12 months.
- OvuSense is a sensor that you insert into your vagina overnight (much like a tampon). The device measures your core body temperature every five minutes and records your data in the connected mobile app. OvuSense can predict ovulation up to 24 hours in advance with 99% accuracy.
- Cost: $299 – gets you the OvuSense device plus a 12-month subscription to the app.
- Priya (Coming Soon)
- Priya is a ring-shaped device that you insert into your vagina that measures your core body temperature continuously to pinpoint your fertile window and predict ovulation.
Walnut Hill OBGYN has more than 100 years of combined experience with doctors who are specialists in services ranging from routine gynecology and obstetrics care to diagnosis and treatment of serious conditions. If you need help starting your family, we also offer complete fertility services.
Talk to one of our doctors today about whether fertility awareness-based methods are right for you.