Tracking your body’s natural monthly rhythms is a great way to get in sync with your cycle and try to prevent pregnancy without using other forms of birth control. Often referred to as “natural family planning,” tracking your basal body temperature, vaginal mucus, and monthly cycle can be up to 99% effective when done correctly all together. If you have irregular periods, notice early signs of pregnancy, or have other issues, talk to your family doctor.[1]

Method 1
Method 1 of 4:

Monitoring Your Basal Body Temperature

  1. 1
    Buy a basal thermometer so you can get a precise temperature reading. Your basal body temperature is your lowest temperature over a period of 24 hours. Your body experiences a slight rise in temperature just after ovulation, and monitoring your basal body temperature over time can help indicate when your peak fertility window is about to begin. Basal body thermometers look basically the same as regular thermometers, but they give more precise readings. They’re available in drugstores and should come with a chart to help you track your temperature every day.[2]
    • A regular thermometer that you might use to check a fever won’t give you exact enough measurements to be helpful. A basal body thermometer measures your temperature’s changes in small increments.

    About Ovulation and Fertility: When you ovulate, one of your ovaries releases an egg that travels down your fallopian tube. If the egg meets a sperm in the next 12-24 hours, it can be fertilized. If it isn’t fertilized, it gets released from your uterus along with your uterus lining and you get your period. Because sperm can live in your body for up to 5 days, you can get pregnant if you have unprotected sex during the 5 days before ovulation and up to 24 hours after you ovulate.[3]

  2. 2
    Take your basal body temperature at the same time every morning. The most accurate way to track your temperature is to take it right when you wake up before you get out of bed and start moving around. Keep the thermometer by your bed and make it a habit to take your temperature first thing in the morning.[4]
    • Most basal body thermometers give you the option of taking your temperature in your mouth or your vagina. Usually, taking your vaginal temperature will give you the most accurate reading from day to day. Whichever way you choose, do it the same way every day to ensure your readings are as consistent as possible.
    • Follow the instructions that came with your thermometer. Generally, you’ll turn on the thermometer and insert it in your vagina or mouth. When you hear it beep, after about 30-60 seconds, remove the thermometer and check the temperature reading.
    • Make sure to sanitize your thermometer after each use. Either wash it with soap and water or wipe it down with a disinfectant.
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  3. 3
    Track your temperature every day so you can see when it tends to change. Use the calendar that came with your thermometer, or track it in an app on your phone. Make sure to record the date as well as the exact temperature so you have the best data to help you understand your fertility window better.
    • Period Tracker, Flo, Eve, Cycles, Ovia, and other apps help you track your period and give you space to write down other daily details, like your temperature, mood, and other symptoms.
  4. 4
    Look for a small spike in temperature that lasts 3 days. After you ovulate, your temperature will increase a little bit for about 3-4 days. This is a small change, which is why it’s so important to have the most precise temperature readings. Look for an increase of about 0.4-1 degree Fahrenheit (0.7-1.8 degrees Celsius). Chances are, your fertility window has ended.[5]
    • It can take a while to get a good understanding of your basal body temperature, but stick with it! Especially when used along with other tracking methods, it can be a very accurate indicator of fertility so you know when to abstain from sex.
  5. 5
    Keep track for a minimum of 3 months to understand your body’s pattern. Until you’ve taken your temperature consistently for a few months, you shouldn’t rely on this method for pregnancy prevention. If your cycle is regular, 3 months’ worth of data should be enough to help you predict your fertility window in the following months.
    • If your cycle tends to be irregular, you may need to take your temperature for 6 months or more before you can rely on the patterns that emerge.
    • Illness, stress, alcohol, lack of sleep, and other factors can also affect your body temperature. That’s why it’s a good idea to use this method with other tracking methods to back yourself up in case your temperature pattern is thrown off for some reason.
    • Accurate data is super important to this method. Be consistent with taking your temperature every single day and keeping track of your findings. If you miss a few days each month, it could really throw off your understanding of your body and make it less likely to effectively prevent pregnancy.
  6. 6
    Avoid sex during your ovulation and fertility window to prevent pregnancy. After 3 or more months of tracking your temperature every day, you can use your findings to try to anticipate when you’ll ovulate next. For the most effective results, use your basal temperature along with tracking your cycle and observing your cervical mucus. Interpret the data in this way:[6]
    • Look at your chart and find the day when your regular spike in temperature happens each month.
    • On a calendar, mark the 2 or 3 days before this temperature spike as the days when you’re likely to ovulate. Remember, your temperature doesn’t increase until 2-3 days after ovulation.
    • Avoid having unprotected sex for at least 5 days before ovulation is supposed to begin, up through ovulation day.
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Method 2
Method 2 of 4:

Checking Your Cervical Mucus

  1. 1
    Begin checking your cervical mucus once your period has tapered off. Cervical mucus changes in texture, color, and smell throughout your cycle. By checking it every day, you can use the patterns you find to predict when your body is fertile.
    • Though the exact days can differ for each woman, you will tend to ovulate between day 11-21 of your monthly cycle, each cycle starting at day 1 when your period begins.[7]

    Combining Methods: For the most effective results at preventing pregnancy, use all of the methods together. The data from each one will give you a much better chance of predicting your fertility window so you can use other forms of protection or abstain from sex during that time. Your cervical mucus will clue you in to when your body is most fertile, your basal body temperature lets you know when it’s most likely safe to resume having unprotected sex again, and your cycle itself will help you predict your fertility rhythm each month.

  2. 2
    Check your mucus at the same time every morning to test its consistency. Wash your hands first, then gently insert your middle finger into your vagina. You may want to swipe your finger from front to back to check for mucus.[8]
    • After your period, you’ll most likely notice that you don’t have any discharge and your vagina may be drier than usual.
    • If you’re using this method in conjunction with your basal body temperature, try to do them at the same time in the morning so it’s easier to keep track of things.
  3. 3
    Observe your mucus until it begins to get thin and stretchy. Every day as you check your mucus, look at it and press it to your thumb to check its texture. As your hormones fluctuate, the characteristics of the mucus will change, too. During the days following your period, you may have no discharge, then slightly cloudy or creamy discharge. Once it takes on the consistency of egg whites, you’ll be at peak-fertility level and have a high chance on getting pregnant.
    • When you’re most fertile, the discharge may even stretch between your fingers without breaking.
    • Ovulation occurs on or after the last day this mucus is produced.
    • Keep in mind that you can still get pregnant during the 5 or so days before you ovulate, so even if your discharge doesn’t quite have an egg-white texture yet, you are still somewhat fertile.
  4. 4
    Keep a written record of your mucus so you can track your body’s pattern. Every single day, write down the color and texture of your mucus. If you’re also tracking your basal body temperature, use the same calendar so you have all the data in the same place. Don’t forget to record the date, too! Here are some examples of detailed entries you might write:[9]
    • 4/22: Mucus is tacky and white.
    • 4/26: Mucus is whitish and runny, like egg whites.
    • 4/31: Period started; heavy flow.
  5. 5
    Avoid unprotected sex when your mucus changes from tacky to creamy. You’re most fertile when your mucus has the consistency of stretchy egg whites, but err on the safe side by avoiding sex for a few days before and after your mucus takes on these qualities. After tracking your patterns for a few months, you’ll start to better predict when you’ll be fertile each month.
    • If you’re tracking your basal body temperature, compare the data. Your mucus will probably turn stretchy and wet several days before your body temperature spikes. Ovulation typically happens between the change in mucus and your temperature spike.
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Method 3
Method 3 of 4:

Tracking Your Cycle on a Calendar

  1. 1
    Mark the active days of your period on a calendar each month. Most women with regular periods have a cycle that lasts between 26-32 days, although some women may have shorter or longer cycles. Day 1 of your cycle will be the day menstruation starts.[10]
    • Your cycle may vary a little from month to month. Stress, illness, weight loss or gain, and other factors could impact your cycle.

    Tip: For the calendar method to be the most beneficial and accurate, it should be used along with another tracking method. On its own, simply tracking your cycle isn’t as effective at preventing pregnancy. For the best data and predictability of your fertility window, use all 3 methods together.

  2. 2
    Track your period for 8-12 months for the best predictability. Mark each day of your period on your calendar with a dot or a circle or some other way to identify it. At the end of each cycle when your period begins again, count the number of days your cycle lasted.[11]
    • Because each cycle can vary a little bit, it will take a little longer to gather enough data to predict your fertility window.
    • If your period is unpredictable or skips some months, consider seeing your doctor to determine if anything else is going on.
  3. 3
    Use the monthly patterns to predict when you’ll be fertile. First, take the shortest cycle you’ve ever tracked. Subtract 18 from the number of days that cycle lasted, and write down that number. Next, take your longest cycle recorded and subtract 11 from that number and write it down. Your fertility window is between those 2 numbers of each cycle. For example:[12]
    • If your shortest cycle was 26 days, 26-18=8. If your longest cycle was 30 days, 30-11=19. This means your fertility window is between the 8th and 19th of each monthly cycle. The 5 days preceding ovulation and the 24 hours of ovulation are your most fertile.
  4. 4
    Avoid having unprotected sex during your fertile window each month. Especially if you’re using only this method, it’ll be important that you either abstain from sex or use another form of protection during this time. This method is really best used to help reinforce the patterns you recognize from the other methods.[13]
    • There are too many factors that can affect the length of your cycle for this method to be completely reliable on its own.
    • If you experience irregular periods, this method may not provide useful information.
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Method 4
Method 4 of 4:

Seeking Medical Care

  1. 1
    Talk to your doctor if you have questions about birth control. Choosing the right birth control is a big decision, and it can sometimes feel overwhelming. Fortunately, your doctor is there to help and you can change your mind whenever you like. Ask your doctor about the risks and benefits of different birth control options.[14]
    • Don’t let anyone pressure you into doing something you don’t want to do. It’s your body, and you get to control how you practice birth control, whether that’s with a pill, a shot, contraceptives, natural planning, or some other method.
  2. 2
    Check with your doctor if you have irregular menstrual cycles. Natural family planning counts on your cycles being regular. If you have irregular cycles, your ovulation day likely varies each month. Talk to your doctor to find out if you need to be concerned about this. They can help you figure out how you can make natural family planning work for you.[15]
    • It's possible that your doctor will recommend a different birth control method if your cycles are very irregular.
  3. 3
    See your doctor if you notice signs of pregnancy. While natural family planning can help you avoid pregnancy, sometimes it fails. If you accidentally have sex during your fertile window, you may become pregnant. Be aware of the early symptoms of pregnancy and see your doctor immediately if you notice the following signs:[16]
    • Missed period
    • Nausea
    • Vomiting
    • Tender or swollen breasts
    • Increased urination
    • Fatigue
    • Moodiness
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Expert Q&A
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  • Question
    Could I get pregnant 10 days after my period?
    Lisa Bryant, ND
    Lisa Bryant, ND
    Licensed Naturopathic Physician
    Dr. Lisa Bryant is Licensed Naturopathic Physician and natural medicine expert based in Portland, Oregon. She earned a Doctorate of Naturopathic Medicine from the National College of Natural Medicine in Portland, Oregon and completed her residency in Naturopathic Family Medicine there in 2014.
    Lisa Bryant, ND
    Licensed Naturopathic Physician
    Expert Answer

    Support wikiHow by unlocking this expert answer.

    Yes, ovulation can happen 10 days after the period has ended.
  • Question
    I've had 2 D&C procedures and I am 35 years old. Am I still at risk of getting pregnant?
    Lisa Bryant, ND
    Lisa Bryant, ND
    Licensed Naturopathic Physician
    Dr. Lisa Bryant is Licensed Naturopathic Physician and natural medicine expert based in Portland, Oregon. She earned a Doctorate of Naturopathic Medicine from the National College of Natural Medicine in Portland, Oregon and completed her residency in Naturopathic Family Medicine there in 2014.
    Lisa Bryant, ND
    Licensed Naturopathic Physician
    Expert Answer

    Support wikiHow by unlocking this expert answer.

    Yes, women can still become pregnant after D&C procedures.
  • Question
    Will the sperm die if I take birth control pills?
    Lisa Bryant, ND
    Lisa Bryant, ND
    Licensed Naturopathic Physician
    Dr. Lisa Bryant is Licensed Naturopathic Physician and natural medicine expert based in Portland, Oregon. She earned a Doctorate of Naturopathic Medicine from the National College of Natural Medicine in Portland, Oregon and completed her residency in Naturopathic Family Medicine there in 2014.
    Lisa Bryant, ND
    Licensed Naturopathic Physician
    Expert Answer

    Support wikiHow by unlocking this expert answer.

    No, oral birth control pills will not kill sperm.
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About This Article

Lisa Bryant, ND
Co-authored by:
Licensed Naturopathic Physician
This article was co-authored by Lisa Bryant, ND. Dr. Lisa Bryant is Licensed Naturopathic Physician and natural medicine expert based in Portland, Oregon. She earned a Doctorate of Naturopathic Medicine from the National College of Natural Medicine in Portland, Oregon and completed her residency in Naturopathic Family Medicine there in 2014. This article has been viewed 1,015,062 times.
23 votes - 83%
Co-authors: 29
Updated: March 13, 2023
Views: 1,015,062

Medical Disclaimer

The content of this article is not intended to be a substitute for professional medical advice, examination, diagnosis, or treatment. You should always contact your doctor or other qualified healthcare professional before starting, changing, or stopping any kind of health treatment.

Article SummaryX

If you want to avoid pregnancy naturally, you should first understand your body’s reproductive cycle so you know when you’re fertile. To track your cycle, you need to use a basal thermometer to check your body temperature every morning. You should look for a spike that lasts between 7 and 12 days, which shows when your body is ovulating. Along with monitoring your temperature, you should observe the texture and color of your cervical mucus every day. When you have thin, stretchy mucus, then that means you’re extremely fertile and have a high likelihood of getting pregnant. Once you know your fertility window, you can avoid having sex during that time. Remember tracking your cycle isn’t an exact science so it’s important to be diligent with your monitoring so your natural contraception can be effective. For more help, including how to track your period cycle to prevent pregnancy, scroll down!

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