Fertility Awareness: Natural Family Planning (NFP)

What is fertility awareness?

Fertility awareness is a collection of methods using your body’snatural and normal functioning to determine the days of the monthyou are most likely to get pregnant. It is also called Natural FamilyPlanning (NFP), the Sympto-Thermal Method, the Ovulation Method, orthe Billings Method.

Fertility awareness or Natural Family Planning is a method of birthcontrol that does not use any drugs or devices. It combines the calendar/rhythmmethod, the basal body temperature method, and the cervical mucusmethod.

The fertility awareness method is used both as a means of preventingpregnancy as well as targeting the most fertile time for getting pregnant.

How does fertility awareness work?

The calendar; basal body temperature; and cervical mucus methodsare combined to give you the awareness of when your body is most fertile.As you become familiar with your body’s ovulation and fertile periods,it provides you the opportunity to abstain from sexual intercourseor use a barrier method during that time.

How do you use fertility awareness?

The first objective within fertility awareness is to become familiarwith your menstrual cycle and to begin charting your fertility pattern.The average menstrual cycle is between 28 to 32 days, however thereare two parts related to your cycle: before ovulation and after ovulation.Here is a glance at an average cycle to give you a gauge for examiningyour cycle:

Day 1: The first day of your menstrual flow is the beginning ofyour cycle.

Day 7: By day seven your egg is preparing to be fertilized by sperm.

Days 11-21: (based on 28-day cycle) Hormones in your body causethe egg to be released from the ovary around this time. This processis known as ovulation. The egg travels through the fallopian tubetowards the uterus. If sperm penetrates the egg, the fertilized eggwill attach to the lining of the uterus and begin to grow. If fertilizationdoes not happen the egg breaks apart.

Day 28: Hormone levels drop around this day causing the lining ofthe uterus to be shed making up your menstrual flow.

It is important to realize that the first part of the menstrualcycle (before ovulation) is different in every woman and can evenchange from month to month. The variation usually occurs from 13 to20 days long. The last half of the cycle is usually more similar forevery women, because there are about 14 days from day of ovulationuntil the start of the next period. This is why women are encouragedto track their cycles and count back 14 days from their LMP to narrowdown their most fertile time of the month.

Calendar tracking method: Your past menstrual cycleswill work as a guide for estimating your fertile times. In order totrack your menstrual cycle and to identify your expected ovulationfollow the step by step process below:

Step 1: Plan on tracking your menstrual cycle for 8 to 12 months.

Step 2: Day 1 will be the first day you start menstruation.

Step 3: Pick the longest and shortest of the cycles from your monthlytracking.

Step 4: The first day of your fertility period is determined bysubtracting 18 days from the length of your shortest cycle. If 26days was your shortest menstrual cycle, take 26 and subtract 18 tocome up with the number 8. This means that the first day of your fertilitywindow starts on the 8th day of your cycle.

Step 5: The last fertile day is determined by subtracting 11 fromthe length of your longest cycle. If 32 days was your longest menstrualcycle, take 32 and subtract 11 to reach the number 21. This meansthat the last day of your fertility period ends on the 21st day ofyour cycle.

The time in between these is considered your fertilitywindow. In the above example, your fertility period would be fromthe 8th day of your cycle to the 21st day of your cycle. Your ovulationis expected during this time frame. You cannot get pregnant everydayduring this time, but it is sometime during this time frame that pregnancycan occur.

If you are trying to avoid getting pregnant, you need to abstainfrom sexual intercourse or use a barrier form of birth control duringyour fertility window. If you are trying to get pregnant, this fertilityperiod would be the targeted time for sexual intercourse.

Basal body temperature method: Your basal bodytemperature measures a change in the temperature that occurs afterovulation and remains elevated until your next period. By lookingat charting from a few cycles, the temperatures can reveal a patternfrom which ovulation can be anticipated. The steps below can helpyou as you begin to track your temperature and identify when you areovulating.

Step 1: Take your temperature orally each morning before you becomeactive.

Step 2: Use a basal thermometer which recognizes small changes inyour temperature. Your body temperature will only rise between 0.4and 1 degree farenheit when you ovulate. Buya Basal Thermometer Now.

Step 3: Record you temperature every day on your fertility trackingcalendar.

If you record it every day, you will see that prior to ovulationyour temperature is rather consistent. As you get closer to ovulation,you may have a slight decline, but it will be followed by a sharpincrease after ovulation. The increase in temperature is the signthat ovulation has just occurred. Because the increase happens afteryou have ovulated, this method is best used by those who have timeto track and study their charts for a couple months, to ensure thebest chances of conception. Illness, lack of sleep, and alcohol ordrug use can affect your temperature and make it difficult to establishan accurate reading.

Cervical mucus method: The consistency of yourcervical mucus changes during the menstrual cycle. In the averagecycle, there are 3 to 4 dry days following a 5 day menstrual flow.

The mucus wetness increases daily, lasting approximately 9 daysuntil the wettest day. Your mucus is easily recognized at this point.It should be abundant, slippery, clear, and very stretchy. It hasbeen described as egg whites.

Ovulation occurs when you have your peak day of stretchy mucus (withintwo days). In order to use the cervical mucus method to identify yourovulation follow the few steps noted below:

Step 1: Collect the mucus from the vaginal opening with your fingersby wiping them from front to back.

Step 2: Record it daily on your fertility calendar by making noteof the color (yellow, white, clear or cloudy), the consistency (thick,sticky, or stretchy) and the feel (dry, wet, sticky, slippery, stretchy).

Step 3: Ovulation is recorded on the day that your mucus is clearest,slippery and most stretchy.

Do not douche or use spermicides which increase your risk for infectionand may wash away or change the appearance of the mucus.

How effective is fertility awareness?

When fertility awareness is used correctly and consistently, itmay reach effective rates around 90%. The effectiveness depends onyour diligence to track and record your fertility pattern and yourcommitment to abstaining from sexual intercourse or using a barrierform of birth control during your fertility window.

Typical use, which refers to the average use, shows a failure rateof approximately 25%. If you are committed to tracking and recordingyour fertility information, you can achieve much higher success rates.

What are the side effects or health risks of fertility awareness?

There are no health risks or side effects associated with fertilityawareness.

Is fertility awareness reversible?

Yes. Fertility awareness does not have any effects on the male orfemale reproductive functioning. Pregnancy is possible immediatelyfollowing the practice of fertility awareness.

How much does fertility awareness cost?

Fertility awareness is free to inexpensive. Free training sessionsare usually available around your community through health centers,pregnancy services, or some churches. Thermometers used to measurebasal body temperatures cost between $10 and $15 and are availableat local drugstores, grocery stores or supercenters. You may use oneof your home calendars to record this information, or you can purchasea fertility awareness chart which cost approximately $8.

What about fertility awareness and sexually transmitted diseases(STD’s)?

Fertility awareness does NOT provide any protection against sexuallytransmitted diseases.

Are there any other physical signs of ovulation?

Your fertility period may be identified by paying attention to otherfunctions of your body. Fertility and ovulation are sometimes trackedor noticed by women who:

  • Experience a change in the cervix
  • Have a slight one-sided pain in the areaof an ovary
  • Softening of the cervix
  • Breast tenderness


Fertility awareness is an acceptable means of birth control for coupleswho have religious concerns related to contraception.

Fertility awareness is also used by couples who are trying to getpregnant. It helps you target your reproductive efforts at the besttimes to get pregnant.

What are the pros and cons of fertility awareness?

  • The Pros of Fertility Awareness include:
    • Effective when used correctly and consistently
    • No side effects
    • Immediate reversibility
    • Inexpensive or free
    • No devices, no drugs, no prescriptionsor office visits
    • Does not contain estrogen which mayincrease the risk of heart problems
    • Acceptable for couples who have religious concerns relatedto contraception
    • Effective for couples who are preventing or trying to getpregnant.
  • The Cons of Fertility Awarenessinclude:
    • Requires diligence from both partners
    • Requires periods of abstinence or backupcontraception for approximately 1/3 of the month
    • Requires consistent and accurate recordkeeping
    • More challenging for women with irregularcycles

View and print an Ovulation Calendar, or useour OvulationCalculator, to better understand your menstruation cycle and ovulation.

Last Updated: 01/2013