• Help & Advice
  • Find a Service
    Close icon
Contraception

Fertility Awareness Methods

Fertility awareness methods, also known as natural family planning, involves working out when you are in the most fertile phase of your monthly cycle and avoiding unprotected sex during this time.

Quick guide

Hormones

No hormones

Mood/Emotions

No effect on mood

STIs

No protection against STIs

Visibility

Invisible but works best with clear communication with your sexual partner(s)

Periods

Periods will stay the same

Lasts for

As long as you want

Acne/Skin

Skin will stay the same

Preventing pregnancy

Effectiveness depends how well you follow the method, if you’re taught by a practitioner and a number of other factors

Starting on this method

It can take up to six menstrual cycles to know your fertile days. You will need to use another form of contraception in the meantime.

Maintenance

Daily monitoring and recording of fertility signs

Fertility awareness requires a high level of commitment and is only recommended for people with regular cycles who would be prepared to manage an unplanned pregnancy if it happened.

How fertility awareness methods work

Fertility awareness works by observing and recording your body’s different natural signs each day of your monthly cycle. The main signs are:

  • Recording your body temperature
  • Monitoring cervical secretions (cervical mucus)
  • Calculating how long your menstrual cycle is

Changes in these fertility indicators can help you identify your fertile time. During your fertile time, you avoid having sex or use additional contraception such as condoms if you don’t want to get pregnant.

Please accept statistics, marketing cookies to watch this video.

Pros and cons

Pros

  • Suitable for people who can’t, or don’t want to, use hormonal contraception
  • Can be used to plan pregnancy as well as avoid pregnancy
  • Up to 99% effective with motivation, training by experienced practitioners, and following the method closely.

Cons

  • No protection against sexually transmitted infections (STIs)
  • Requires using additional contraception (like condoms) or avoiding sex during fertile days, which is also the time when most people’s libido (sex drive) is the highest
  • Failure rates may be as high as 24 in 100 for those who use only one method to measure where they are in their cycle, haven’t been trained or unreliably calculate their cycle 
  • Relies on proper teaching from practitioners and understanding to be effective 
  • Can take a few cycles to learn and work out how to predict your fertile days, use condoms during this time
  • Requires daily monitoring and recording 
  • Can only be used if you have a very regular cycle
  • Effectiveness impacted by illness, stress, travel, change of routine 
  • Demands a high level of commitment from both you and your sexual partner(s)

 

How to use the fertility awareness method

Fertility awareness should be properly taught by a specialist teacher. The information included here is to provide an idea of what how this method works only. Visit Fertility UK at www.fertilityuk.org to find a clinic near you where you can receive this training which may involve a cost.

Your fertile period generally lasts around 8-9 days. This is because eggs can live for 24 hours (and there can sometimes be a second egg released after 24 hours) and sperm can also live inside the body for up to seven days, so if you had sex seven days before ovulation you may still become pregnant.

There are three main monitoring techniques that can help you work out when you are fertile so you can avoid sex or use contraception such as condoms during those days. It is recommended that you do all three of these methods to maximise its reliability.

Menstrual cycle length

Measure and record the length of your menstrual cycle. A menstrual cycle is on average 28 days. Measuring when it starts and ends will give you a rough idea of when you are fertile and when you will be ovulating. This by itself is not reliable enough to know when you are fertile.

Temperature method

There is a small rise in body temperature following ovulation. To track your basal body temperature (your temperature when your body is at rest), follow the steps below:

  1. Measure your temperature before you get out of bed before eating, drinking or smoking (To get an accurate reading you will need to use a digital thermometer or a thermometer designed for family planning)
  2. Record the results
  3. Repeat each day at the same time
  4. Look for 3 days in a row where your temperature is higher (normally by around 0.2C).
  5. This rise in temperature is the end of your fertile window and you are likely to be protected from pregnancy
  6. You are most fertile in the days before this increase in temperature so you should avoid sex or use non-hormonal contraception (e.g. condoms) during these days

Your body temperature can be affected by many factors including sleeping longer or shorter, a lack of sleep, stress, alcohol, travel, medications, illness, the list goes on! If your life is regularly affected by any of these, this might not be the best method for you as your menstrual cycle and ovulation will be more likely to change each month and therefore harder to predict.

Cervical mucus

Your cervical mucus changes in colour, consistency and quantity throughout your menstrual cycle. It can be used to find out where you are in your cycle and whether you are fertile.

To check your cervical mucus place your middle finger into your vagina up to the middle knuckle, rub between your fingers to get an idea of its consistency. You should then record everything about your mucus for that day

What to look out for:

  • After your period – Vagina will feel quite dry and there won’t be much, if any, mucus
  • Before ovulation – Mucus will be white, sticky, moist and creamy. This is the start of your fertile period
  • Immediately before ovulation – Mucus will be wetter, clearer and slippery like raw egg white. This is when you are at your most fertile
  • After ovulation – Mucus will become thicker and stickier or there may be less of it. After 3 days, you are no longer fertile

Are fertility awareness apps reliable?

There are phone apps that you can use to record your temperature which will then calculate when you are fertile for you which can reduce the risk of human error. But the reliability and effectiveness of these apps are not known.

Your menstrual cycle and ovulation signals (temperature) can be affected by many factors – for example, maybe you’ve gone on holiday and you’re in a different time zone, or maybe you’re stressed or ill – The app won’t know this and could then mistakenly give you the go ahead to have unprotected sex when you are actually fertile.

If you are going to use this method, it’s best to have an understanding of your cycle and how it is affected by your lifestyle and use other fertility indicators as well (changes to cervical mucus) rather than relying on technology alone.

Who should use this method

This method can be difficult to follow and its effectiveness is reduced by many factors. To be effective this method is best suited to someone that:

  • Is organised – they can remember to keep a thermometer by their bed and something to record the results in
  • Is committed and motivated to following the method
  • Doesn’t drink much alcohol and doesn’t get hangovers
  • Wakes up at the same time every day and doesn’t have lie-ins
  • Has regular menstrual cycles
  • Has a routine and doesn’t do shift work
  • Don’t travel much (especially in different time zones)
  • Doesn’t suffer from stress
  • Will use alternative contraception on fertile days
  • Isn’t nearing the menopause and hasn’t recently started their period
  • Doesn’t have casual sex (it is easier to follow with the support of your sexual partner)
  • Wouldn’t be devastated if they got pregnant in the next year (other methods are far more effective)

Other factors reducing its effectiveness
Emergency contraception can bring your period forward or delay it
Pain relief, antihistamines and some antibiotics can affect fertility indicators

The fertility awareness method may not be the most effective form of contraception, or may not be suited best to you and your lifestyle but understanding where you are in your menstrual cycle can be useful regardless of whether you’re having sex that could end up in pregnancy or not.

When to start the fertility awareness method

You can start the fertility awareness method whenever in your cycle. But it can take 3-6 months to fully understand your cycle and to confidently be able to predict your fertile days. This means you should use contraception in the meantime.

This adjustment time needed to understand your cycle may be longer if you have recently come off hormonal contraception. You should wait at least three complete cycles after coming off hormonal contraception or until your periods are regular and predictable before starting this method.

This method is not suitable if you are nearing the menopause, if you have irregular periods or if you have recently started your period.

Starting fertility awareness methods after pregnancy

This adjustment time needed to understand your cycle may be longer after pregnancy or you have recently come off hormonal contraception.

After giving birth

You can get pregnant from as little as three weeks after giving birth.

Your period and cycle can take a while to become regular again making this method unreliable until this time.

It is possible to use the Lactational Amenorrhoea Method (LAM) after pregnancy. This is only effective if:

  • You are breastfeeding FULLY (regularly during the day and night, without bottle feeds or dummies and not including breast pumping)
  • Your baby is under six months old
  • Your period hasn’t returned

If all of the above apply, you are unlikely to get pregnant as the hormone released to cause you to make breast milk can stop your body producing the hormones that control your periods. However, fertility can quickly return with any changes to breastfeeding and you can get pregnant before your period starts again.

After an abortion or miscarriage

You can become pregnant from two weeks after an abortion or miscarriage.

Your period and cycle can take a while to become regular again making this method unreliable until this time. You should use contraception until your periods and cycle has returned to normal pattern.

Always speak to your midwife, GP or nurse at a sexual health clinic to check this is the right method for you

FAQs

Can I use the fertility awareness method if my periods are irregular?

If you have irregular periods it can be difficult to work out when you are fertile. it’s best to use a different method of contraception that will be more reliable and effective.

What should I do if i want to have sex during my fertile time?

If you want to have sex during your fertile time, you should use contraception like condoms or avoid vaginal sex. If you’re ever unsure if you are fertile, it’s best to use contraception.

Note: Pulling out is not a method of contraception and is not an effective way of preventing pregnancy.

More FAQs about contraception

Unsure which contraception method is best for you?
  • On this page
    • Unsure which contraception method is best for you?

    Other Stuff you might find useful…

    Info

    Contraception during perimenopause and menopause

    Contraception
    30/5/23

    Before you have your coil or implant

    Contraception
    Advice

    I forgot my pill, patch or ring

    Contraception
    Real Stories

    The Contraceptive Implant: Annie’s story

    Contraception
    Info

    Contraception: FAQs and Myth-busters

    Contraception
    Advice

    Talking to your partner about contraception

    Contraception
    Info

    Vasectomy (Male Sterilisation)

    Contraception
    Info

    There’s a condom for everyone

    Contraception
    Real Stories

    Visiting a sexual health clinic: Rachel’s story 

    Contraception
    Info

    Get free condoms

    Contraception
    Our friendly staff are here to help
    Find a Service near you

    100% free & confidential