08/26/2025 11:25 a.m.

Fertility Awareness Your Most Common Questions Answered

Dr. Niels van de Roemer
Dr. Niels van de Roemer Medical Adviser

Why Is It Important to Be Aware of One’s Fertility?

Fertility awareness helps you identify your fertility status and how it links to your health. A woman’s reproductive period averages about 37 years of her life. Generally, from your first period till menopause, the female reproductive system goes through cycles of changes. This affects all areas of your life, so learning about the female cycle helps you care for your body.

Your period is the most easily noticeable event in your menstrual cycle. Therefore, if it comes too early, too late, or disappears completely, it tells you a lot about your fertility and reproductive health. Other fertility signs aren’t as noticeable, so it’s a little more complicated to keep track.

In a regular menstrual cycle, multiple eggs develop in the ovary, but only one matures and is released at ovulation. Although ovulation is an important milestone, you might not notice it. Some women may get their period without ovulating (anovulatory cycles). This is more common in young girls who have just started getting their periods and older women going through menopause.

Women with very short or long cycles (less than 17 days or longer than 60 days) have more frequent anovulatory cycles. But even women with average-length menstrual cycles may skip ovulation. Studies show that 3.4% to 18.6% of women experience anovulation.

Couples benefit from knowing when and if ovulation has occurred. This helps them time sexual intercourse with the fertile days. Getting the timing right is vital because women are only fertile for a short period. A woman is fertile for a maximum of 12-18 hours, but the lifespan of sperm in the reproductive tract extends their fertile window up to six days each menstrual cycle.

If you’ve tried to get pregnant for longer than 12 months, setting up an appointment with a fertility specialist may be next. Your doctor will have lots of questions about your cycle, so monitoring your fertility prepares you for the appointment.

Furthermore, several health issues can influence the menstrual cycle. Conditions that may interfere with it include endocrine and metabolic disorders, tumors, anatomical changes, or pelvic inflammatory diseases.

Remember, not every missed or delayed period signals trouble. Fertility awareness with your Daysy tracker helps you appreciate how your body operates normally so that you can figure out when things go wrong. And when you seek help from a doctor, all the information you’ve gathered about your cycle comes in handy.

What Are the Three Fertility Awareness Methods?

Fertility expert at Daysy, Dr. Niels Van De Roemer, describes Fertility awareness methods as techniques for recognizing the fertile days of the menstrual cycle. They may be symptoms or calendar based.

Symptoms-based methods involve monitoring fertility signs such as cervical fluid and basal body temperature. The two-day method, cervical mucus method, and the symptothermal method fall under this category.

Calendar based methods of fertility awareness include the standard days method and the calendar rhythm method.

Here are the three most popular fertility awareness methods:

Calculothermal Method

Each night while you sleep, your core temperature resets. This is your basal body temperature (BBT) which you can measure every morning with the Daysy fertility tracker. It uses the calculothermal method which combines BBT monitoring with statistical analysis.

Unlike the simple temperature method, the calculothermal method accounts for the fertile and infertile days in each cycle. The Daysy fertility tracker has a self-learning algorithm that can predict events in your cycle using previously gathered data.

Start each day by inserting your fertility tracker into your mouth. It’s important not to delay taking your temperature in the morning. The longer you wait, the more energy you burn, which makes you warmer.

Measuring your BBT orally is your best bet for accurate readings. Daysy can differentiate between your fertile and infertile days with 99% accuracy. On the other hand, body fat percentage, surrounding temperature, and other factors may influence the readings from devices you wear on your wrist or arm, so they’re not as reliable.

Your BBT is linked to your menstrual cycle and helps you learn more about your reproductive health. A typical BBT graph has two phases, coinciding with the two phases of your menstrual cycle.

BBT is lower in the first phase of your cycle due to estrogen. After egg release, the corpus luteum produces lots of progesterone. This hormone maintains the endometrium and makes you warmer for the second phase of your cycle.

If there’s no pregnancy, your BBT drops as the corpus luteum dries up and stops producing progesterone. Within a few days, the endometrium breaks down and comes out as menses. Monitoring your basal temperature changes can tell you about the phases of your cycle. If you’d like to learn more about your body, use your Daysy fertility tracker to keep up with your BBT and menstrual cycle.

Cervical Mucus Monitoring

The donut-shaped neck of your uterus has glands that secrete fluid. Usually, cervical mucus plays two essential roles — it keeps contaminants out of the uterus and is crucial for female fertility.

Here’s a simple guide to what normal cervical mucus looks like:

  • Dry or no cervical fluid
  • Sticky yellow or white paste
  • White creamy-like yogurt texture
  • Slippery or stretchy
  • Clear watery fluid

The type of cervical secretion depends on the phases of the menstrual cycle. Immediately after your period ends, you may have dry cervical fluid or none. About four to six days after your period, cervical secretions become pasty or sticky. It then progresses to a yogurt-like consistency for the next few days. From day 10 to 14, cervical mucus becomes stretchy — think of raw egg white consistency. In the second half of your cycle, from day 14 to 28, the cervical fluid becomes dry again.

Changes in the cervix and its secretions are under hormonal control. Estrogen peaks before egg release, changing the cervical mucus from a thick paste to a slippery fluid. It lets sperm swim through to the uterus during your fertile period.

Calendar Method

The calendar method involves monitoring and calculating the days of your cycle. Over several months, you record the details of each menstrual cycle. Then use this information to calculate your fertile and infertile days.

Other well-known fertility awareness methods are:

  • The symptothermal method — This involves observing fertility signs that signal various phases of the menstrual cycle. Commonly monitored fertility signs include cervical mucus and BBT.
  • The two-day method — This is a variation of cervical mucus monitoring.
  • The standard days method — Couples avoid unprotected sex on days 8 to 19 of the menstrual cycle.

How Do You Use the FAM Method?

Fertility awareness is a great way to understand the female reproductive system and how it works. You may use one method or combine multiple techniques.

Here’s how to use the three most popular fertility awareness methods:

Calculothermal Method

The calculothermal method uses your BBT measurements and data from your previous cycles. Immediately you wake up in the morning, place a thermometer in your mouth to record your basal body temperature.

Devices such as the Daysy fertility tracker are sensitive to the slight temperature change after ovulation. With your BBT and data from your cycle, it calculates your fertile and infertile days.

Here's how to use your Daysy fertility tracker in the morning:

  • Push the button twice to turn it on and activate it
  • Stick the sensor under your tongue and close your mouth
  • Wait till it has recorded your temperature
  • Check the lights to know your fertility status

Immediately after ovulation, your BBT peaks under the influence of progesterone but begins to decline as the hormone drops a few days before your period. When a new menstrual cycle starts on day one of menstruation, your BBT is back in the low phase. If you’d like to see how your BBT varies, get the DaysyDay app as well.

Cervical Mucus Monitoring

You can analyze your cervical mucus daily to understand your fertility. Start tracking from the day after your period ends.

Collect cervical mucus by wiping your vulva with a tissue, checking your underwear, or inserting clean fingers into your vagina. Roll it between your fingers and check the following:

  • Color
  • Consistency
  • Sensation

Here are the categories of cervical mucus according to your fertility status:

  • Type 1 (Lowest fertility) — Feels rough and dry/No secretion
  • Type 2 (Low fertility) — Feels damp/No secretion
  • Type 3 (Intermediate fertility) — Thick or creamy mucus that feels damp
  • Type 4 (High fertility) — Transparent or white fluid that feels slippery or smooth

Calendar Method

To use the calendar method, you must track your cycle for several months. A new menstrual cycle begins on the first day of your period. Count the duration of each menstrual cycle till you have a record of at least six. Here’s how to calculate your fertility using the calendar method:

First fertile day

  • Subtract 18 from your shortest menstrual cycle to get the number X
  • Count X days from day 1 of your cycle to get your first fertile day

Last fertile day

  • Subtract 11 from your longest menstrual cycle to get the number Y
  • Count Y days from day 1 of your cycle to know your last fertile day

Mark day X to day Y in red on your calendar to identify your fertile window.

Unfortunately, the calendar method isn’t very reliable, especially if all your cycles are under 27 days. Additionally, it doesn’t identify other critical events in your menstrual cycle, such as ovulation.

Why is Fertility Awareness Unreliable?

Fertility awareness methods track the menstrual cycle to distinguish between your fertile and infertile days. Identifying your fertility status helps you time sexual intercourse to conceive or avoid pregnancy.

Unfortunately, fertility awareness methods aren’t always reliable. One factor that affects their effectiveness is improper use.

Despite these challenges, fertility awareness may help couples trying to have a baby. A woman’s fertile period is about six days in an average 28-day cycle. The egg released at ovulation is only viable for 18 to 24 hours, but sperm can stay alive in the reproductive tract for up to five days.

Tracking your cycle helps you figure out the best time to try for a baby. Couples without fertility issues using fertility awareness methods have an 85 to 90% chance of conception within 12 months.

But there’s more.

If you need medical assistance to conceive, you can share whatever information you learn about your fertility with your doctor. This helps them understand how your body works and figure out a way to help. Tools such as the Daysy or Lady-Comp fertility tracker help you become aware of your fertility.

Learn more

Unlock the secrets of cervical mucus as a natural fertility signal. Learn how it changes throughout your cycle, and how to track it effectively to support your journey to conception.

Cervical Mucus

The fertility tracker method is a modern, digital evolution of natural family planning. It eliminates common sources of error – ensuring ovulation is accurately detected and recorded.

The Fertility Tracker Method

Learn how to determine your fertile days with natural family planning – hormone-free, self-directed, and in harmony with your cycle.

Natural Family Planning

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