Natural methods

Menstrual cycle length

What is it? 
With this method, you keep a record of when you have your periods. After a couple of months, you can predict when you’ll be ovulating. But be aware of this:  it only works if you have regular periods.

How do you prevent pregnancy?
Make sure you use condoms for penis-in-vagina sex 7 days before and 2 days after ovulation.

How do you know when you’ll be ovulating?

• Ovulation is approximately 14 days before your next period. So when your period starts, you’ll know when you were last ovulating. 
• Keep a record of the dates of your periods for a couple of months.
• Are there always roughly the same number of days between your periods? Then you can approximately predict the next ovulation.
• There are also apps that help you to do this. But there is no evidence that these apps work properly.

Why is it less safe?

• Ovulation is not always on the same day.
• If you’re still young, your periods won’t yet be regular.
• Stress, illness, lack of sleep, alcohol and medicines can affect your menstrual cycle.

If you really don’t want to get pregnant, use a contraceptive.

Body temperature checks

What is it? 
This method helps you predict when the next ovulation will be. Your body temperature rises after ovulation by 0.3 to 0.5 degrees.  But be aware of this:  it only works if you have regular periods.

How do you prevent pregnancy?
Make sure you don’t have penis-in-vagina sex 7 days before and 2 days after ovulation.

How do you know when you’ll be ovulating?

• Take your temperature every morning as soon as you wake up. Do that using a thermometer.
• If your body temperature has slightly risen, you have just ovulated. So you’ll only know after ovulation that it has taken place.
• You’ll have your period 14 days later.
• Keep a record of this for several months. Then you’ll be able to predict approximately when the next ovulation will be.

Why is it less safe?

• Your body temperature can vary. That makes it difficult to see when it has gone down.
• Your temperature can be affected by illness, stress, lack of sleep, alcohol and medicines.
• When you get up in the morning, your temperature immediately rises.
• Most women and girls don’t have a regular menstrual cycle.
• There are also apps and devices to help you with this. But there is no evidence that the apps work properly.

If you really don’t want to get pregnant, use a contraceptive.

Cervical mucus monitoring

What is it? 
Women can use their cervical mucus (vaginal fluid) to see when ovulation is about to happen. Your cervical mucus then becomes more transparent and quite elastic.

Why is it less safe?

• It is difficult to tell from your mucus when you’ll be ovulating.
• You are already fertile 5 days before ovulation.

This method is very unreliable. If you really don’t want to get pregnant, use a contraceptive.
 

Combining the methods

You can also combine the fertility awareness methods. Then you’re more likely to predict ovulation accurately.

An example: when will you be ovulating?

• You keep a record of your periods for a couple of months. At the same time, you take your temperature every morning. Keep a record of that too.
• If your body temperature has risen, you’ve just ovulated. Work out whether this happens at the same time every month. Then you can predict your ovulation.
• Monitor your cervical mucus when you’re expecting to ovulate. If the mucus is transparent and elastic, then you are about to ovulate.

Why is it less safe?

• It’s a lot of work and not easy to do properly every day.
• Understanding exactly how to predict your ovulation with this method isn’t easy. So it’s advisable to do a fertility awareness training course.
• If you’re still young, you don’t yet have regular periods. So it’s difficult to predict ovulation.
   

If  you really don’t want to get pregnant, use a contraceptive. Then you can be sure you’re using a reliable method to prevent pregnancy.