Overview

Fertility awareness (also called natural family planning) is a way to find out which days of the month you are most likely to get pregnant. It’s done by tracking the changes your body goes through during your menstrual cycle. Learning about these changes can help you know when your ovary releases an egg (ovulates). You can then time vaginal sex to try to get pregnant or to try to avoid pregnancy.

If you have regular periods, you are probably able to get pregnant for about 6 days each month. This includes 5 days before you ovulate to the day after you ovulate. This is because sperm can live for 3 to 5 days in your reproductive tract and an egg is fertile for about 24 hours after you ovulate.

To avoid pregnancy, you do not have vaginal sex on your fertile days. Or you can use a barrier method of birth control, such as a condom or diaphragm. If you want to get pregnant, you have vaginal sex during these days.

Fertility awareness is most effective if you have regular periods and are able to keep close track of your menstrual cycle and physical signs of ovulation.

Why It Is Done

Fertility awareness is done to help you learn when you are likely to ovulate. This information can help you to:

• Become pregnant. Pregnancy is most likely to occur when vaginal sex occurs close to the time of ovulation.
• Avoid pregnancy. You can avoid vaginal sex or use another method of birth control around the time of ovulation.

How To Prepare

Before you use fertility awareness, you will want to find your pattern of ovulation. You can do this by keeping a record of three or four of your menstrual cycles. If you are trying to not become pregnant while you find your pattern, you can use a method of birth control that doesn't affect ovulation. Some examples are a condom, a diaphragm, and the copper intrauterine device (IUD). Or you can choose to not have vaginal sex.

There are several ways to find out when you ovulate. And there are apps that can help you do this. Some ways include checking your basal body temperature (BBT), checking your cervical mucus, and monitoring your hormones. It can be helpful to use some of these methods at the same time.

How It Is Done

If you have regular periods, you have about 6 fertile days each month. These are the days when you can get pregnant. To find out when you are fertile, you must know when you release an egg (ovulate). Fertile days include 5 days before you ovulate to the day after you ovulate.

There are several ways to find out when you are fertile. There are apps that can help you do this. To get the result you want, you may need to use some of these methods at the same time.

Here are some common methods.

• In the standard days method, you keep track of when you start your period. This tells you how long your cycle is. It also tells you how regular it is. With this information, you can guess which days of the month you are most likely to be fertile. This is between 8 and 19 days before your next period. This method works best if you have regular cycles that are usually between 26 and 32 days long.
• In the basal body temperature (BBT) method, you take your temperature right after you wake up every day. This gives you your BBT. This is your lowest temperature during the day. Your BBT goes down 1 to 2 days before ovulation. Then it goes back up 1 to 2 days after you ovulate. If you use care to track your BBT, you may be able to guess when you are fertile.
• In the cervical mucus (Billings) method, you check the mucus in your vagina every day. You record the amount, stickiness, and color of the mucus. The mucus changes during your menstrual cycle. Just before and during ovulation, you will have more cervical mucus and it will be thin, clear, and slippery. Just after ovulation, the amount of mucus decreases and it becomes thicker, sticky, and cloudy. If you track it, you may be able to guess when you are fertile.
• In hormonal monitoring, you buy a kit that lets you check the amount of a hormone in your urine. The amount of the hormone tells you if you may be ovulating.
• In the combined (symptothermal) method, you use your BBT and changes in your cervical mucus to guess when you ovulate. You may also use hormone tests and watch for signs of ovulation. These include tender breasts, belly pain, and mood changes.

You should check your body changes using these methods for several months before you use them to avoid pregnancy.

Be sure to tell your doctor about any health problems you have or medicines you take. If you are trying to avoid pregnancy, your doctor can help you choose the birth control method that is right for you.

Risks

There’s a risk that fertility awareness may not work.

• You may not succeed in getting pregnant.
• You may have an unplanned pregnancy.

How Well It Works For Birth Control

Fertility awareness does not work better than other birth control methods. In the first year of use:

• When fertility awareness is used exactly as directed, it is 95% effective for preventing pregnancy. That means that 5 out of 100 people will have an unplanned pregnancy.
• When it is not used exactly as directed, it is 76% effective for preventing pregnancy. That means that 24 out of 100 people will have an unplanned pregnancy.