Rhythm Method

What Is the Rhythm Method of Birth Control?

The rhythm method is a type of natural birth control that involves tracking your menstrual cycle on a calendar. It helps you predict when you ovulate, which is when you’re most likely to get pregnant. Knowing this can help you avoid sex or use protection during those days to prevent pregnancy.

Some couples also use this method to try to get pregnant by having sex during those fertile days.

The rhythm method is sometimes called the calendar method because it involves tracking your cycle on a calendar. It’s part of a group of approaches called natural family planning or fertility awareness methods.

How does it work?

You’re only able to get pregnant during a few days each menstrual cycle. The rhythm method works by using your past cycles to estimate when those fertile days happen. Once you know this, you can avoid sex or use a barrier method, like condoms, during that time.

This method is based on ovulation, which is when your ovary releases an egg. The egg moves into your fallopian tube, where it can be fertilized by sperm. While the egg only survives for about 24 hours, sperm can live inside your body for up to five days. This creates the “fertile window” when pregnancy is possible.

Here’s how the rhythm method usually works:

• A typical menstrual cycle lasts 28 to 32 days. The first day of your period is day one.
• Ovulation often happens around day 14.
• Pregnancy can happen if you have sex in the days just before ovulation and within 24 hours after.
• Using the rhythm method helps you avoid having unprotected sex during your most fertile time.

The more months you track your cycle, the easier it becomes to notice a pattern. Over time, you can better predict when ovulation usually happens.

Is the rhythm method accurate?

It works best if you have a regular, predictable cycle. If your cycle is shorter than 26 days or longer than 32 days, this method may not give you accurate information. Even with regular cycles, tracking mistakes or natural changes in your body can make this method less accurate.

Is it effective for birth control?

When used alone, it’s not a very reliable form of contraception. The effectiveness depends on:

• How consistent you are about tracking your cycle
• If you avoid sex or use birth control when you’re fertile

The rhythm method is more effective when you use it along with barrier methods of birth control.

How do I calculate my rhythm method safe days for sex?

You can use the steps below to find your fertile days:

• Day one is the day you get your period. Mark this on a calendar with an X.
• Mark the first day of your next period with an X.
• The number of days between the Xs is the length of your cycle.

Plan on tracking your menstrual cycle on a calendar for at least six months before you use the rhythm method as birth control.

Once you’ve tracked for six months:

1. Find the longest and shortest cycles from your calendar. For example, the longest might be 31 days, and the shortest might be 28.
2. To find the first day of your fertility window, subtract 18 from your shortest cycle. If your shortest cycle was 28 days, subtract 18 from 28, which gives you 10. That means the first day you are fertile is the 10th day of your cycle.
3. To find the last day of your fertility window, subtract 11 from your longest cycle. If 31 was your longest cycle, subtract 11 from 31. This means the 20th day of your cycle is when your fertile window ends.
4. Using this example, you would not have sex or you would use protection on days 10 through 20 of your cycle.

Your fertile window is when pregnancy is most likely. So, avoid unprotected sex if you don’t want to get pregnant. If you do want to get pregnant, have sex more often during this time.

What are the benefits of using the rhythm method?

The rhythm method and other fertility awareness methods may be appealing if you:

• Don’t want the side effects or risks of hormonal birth control
• Don’t want to take artificial hormones
• Have religious or personal reasons for avoiding certain types of birth control
• Want a method you can change or stop anytime
• Prefer a free or low-cost option

What is the biggest drawback?

The biggest drawback is that it’s not as effective at preventing pregnancy as other birth control methods. It can be hard to be 100% sure what days you’re fertile.

Some of the other cons of the rhythm method are:

• Tracking your cycle can be frustrating.
• This method doesn’t protect against sexually transmitted infections (STIs).
• It can be hard if you have irregular periods.
• You have to avoid sex or use a barrier method for about 10 days each cycle.
• You need to wait several months to see a pattern.
• This method doesn’t help with period symptoms like other birth control methods do.

How can I track my fertility naturally?

These methods can be used along with the rhythm method to help you learn your body’s patterns and predict when you’re most fertile:

• Cervical mucus: Your cervical mucus changes throughout your cycle. When it’s clear, stretchy and like egg whites, that’s a sign that ovulation is coming.
• Basal body temperature: Take your temperature every morning before getting out of bed. Your body temperature rises slightly after ovulation.
• Cervical changes: Your cervix becomes softer, higher and more open around ovulation.
• Ovulation kits: At-home ovulation tests detect hormone changes in your pee to predict when ovulation is coming.
• Physical changes: You may notice breast tenderness or mild ovary pain during ovulation.