Charting: Cervical Mucus and BBT

As a woman, the first step to understanding birth control is to understand your fertility pattern and the changes your body goes through each month to prepare you for a possible pregnancy. Once you start recognizing the way your menstrual cycle, your body temperature and your cervical mucus change, it is easy to practice natural family planning.

Menstrual Cycle

Every woman from puberty to menopause experiences a monthly cycle called the menstrual cycle, which begins with the first day of your bleeding or periods. This cycle can be divided into two phases, one before ovulation and one after ovulation. Ovulation is the process by which an egg is released every month, which can be fertilised by a male sperm.

Usually, after day 1, the bleeding continues for 4 to 5 days and already by day 7 a few of the ovarian follicles in the ovaries start maturing to become eggs. The time between day 7 and 11 is also when the uterus lining starts to thicken, readying itself in case an embryo is formed later in the cycle. If you have a 28-day cycle then by day 14, the egg that has matured the most is released from the ovary while the other eggs cease to grow. This is the time when you are ovulating.

In the second phase, the egg starts its journey from the ovary to the uterus through the fallopian tube. If a sperm is present at this stage, then fertilisation will take place and the fertilised egg will then attach to the uterus. If fertilisation does not occur, then within a day or two the egg dries up and by day 25 the hormone levels in your body drop. By day 28, you will get your next period and another cycle will start.

Although all women have the same process of menstruation, their cycle length may vary from 27 to 32 days or possibly even more. Additionally, other factors such as fatigue, stress or illness, can throw off your cycle.

For effective birth control, the important phase is the first phase when ovulation is about to occur. It is during this stage that sperm may fertilise an egg. Depending on the length of a woman’s cycle, this phase may last from 13 to 20 days.

Charting the Menstrual Cycle

Regardless of the length of your cycle, an egg is released every month in your body about 14 to 16 days before the next menstrual period. By charting your cycle for a few months, you can learn both the average length of your cycles as well as make a prediction as to when ovulation occurs. Once you know this, you can avoid pregnancy by abstaining or using another form of birth control, such as a contraceptive sponge, for about 7 days. Why seven days? Because sperm can live inside you for about five days, which means that you need to avoid unprotected sex for five days before you ovulate. The remaining two days account for the day of ovulation and the day after, as an egg is viable for just 24 hours after the ovulation cycle.

To chart your menstrual cycles, you can use a normal calendar to mark the first day of your cycle for at least six consecutive months. Within the next few months, you will get an idea of the length of your cycle and then you can make an assumption as to the when you are ovulating. Looking for signs of ovulation, such as discomfort in the lower abdomen, can help you determine when ovulation may occur. However, this technique is not that accurate.

Just charting your menstrual cycle is sometimes not enough as a method of birth control, because even as an individual your fertility pattern may show variations each month. To help make this type of charting more precise, it is a good idea to also chart your basal body temperature and/or cervical mucus changes.

Basal Body Temperature

Although you probably don’t notice it, all women have their core body temperature rise slightly at the onset of ovulation, which remains elevated until your period. Therefore, charting your temperature every day is a good way to know when you are about to ovulate.

Basal body temperature (BBT) is the temperature of your body when it is at rest. When using this method, it is always suggested that you take your temperature as soon as you wake up, before you get out of bed. During the first phase of your cycle, your temperature will normally be in the range of 96°F to 98°F. As ovulation approaches, it will rise to around 97°F to 99°F and stay elevated for a few days. This increase in body temperature is actually caused by the hormone progestrone to facilitate a warmer and more comfortable environment for a possible pregnancy.

Charting Basal Body Temperature

Basal body temperature should be taken first thing in the morning, before any physical activity and after your body has completely rested. You can choose to take your temperature orally, vaginally or rectally. Ideally, your temperature should be taken at the same time everyday as it can vary according to the time you take it at. You should also not eat or drink before recording the temperature. Special basal body thermometers are available that are more precise than regular thermometers and can show your temperature changes in increments of one-tenth of a degree.

Starting on day 1 of your cycle, take and record your temperature every day. You may find it helpful to put this information down into a graph so that you can see the changes in your temperature easily. Typically, you will notice a rise of 0.4 degrees at the time of ovulation. This temperature has to be higher than any recorded prior to that in the cycle. If this high temperature is maintained for 3 to 4 days, then this is the time you ovulated. If you become pregnant, your basal body temperature will continue to remain high for more than 18 days.

Charting your basal body temperature has to be done for a few months until you get familiarised with your body pattern and see the sharp or gradual increase in temperature. Also, this method will only alert you to ovulation after the fact until you have been doing this for some time and can more accurately judge your ovulation cycles. Therefore, to prevent pregnancy, you will need to use other methods of birth control, like a diaphragm until you are confident enough to rely on this natural birth control alone. Using an ovulation predictor kit or a cervical mucus chart are comparatively better in predicting the fertile phase.

Cervical Mucus

The mucus produced by the cell lining of the cervix changes considerably throughout your menstrual cycle. Charting the appearance, sensation and elasticity of the mucus can give you a very good idea of when you are about to ovulate. These changes are actually due to the rise in estrogen levels in the body.

Charting Cervical Mucus

You can check your cervical mucus either when you wipe with toilet paper or you can take a sample with your fingers. Usually it is best to record your mucus changes at the same time every day, or even 3-4 times a day, throughout your cycle. The appearance of your cervical mucus will change according to the phase of your menstrual cycle. The typical characteristics of cervical mucus are:

• Just after your period, there is a dry phase for 3 to 4 days when no mucus is clearly visible
• Slowly, with the ovulatory phase approaching, the mucus will start to appear as a white or creamy liquid. If you touch this mucus, it will easily break if you try to stretch it between your fingertips.
• As the days progress and your body’s estrogen levels rise, the mucus will get thicker and secrete in more quantities though it may still be creamy
• As you approach ovulation the mucus will appear thin and watery like raw egg white. When you stretch it between your fingertips, this mucus may stretch for several inches before breaking
• This particular mucus is the time when sperm can easily enter through the cervix and fertilisation may occur
• Within a day or so, the egg white mucus may again become creamy or white. This will tell you that the previous day was the peak day when you had the highest chance of getting pregnant.
• As your period approaches, your mucus will again become lesser and lesser as well as in appearance

Pros and Cons of the Charts

The charting of your menstrual cycle, basal body temperature and cervical mucus is a very good way to understand your body and the typical changes that occur every month. Your daily ovulation chart can help you predict the time of ovulation and abstain from intercourse during that time. Conversely, if you would like to get pregnant, these methods can also be used to help you identify your most fertile time. As a type of birth control, charting is good for those who are not comfortable with other birth control methods, like birth control pills or Depo Provera.

Since there are no artificial hormones involved, birth control side effects are virtually non-existent with charting. Additionally, the cost of birth control is significantly reduced, as all you need is a calendar, a pen, perhaps a thermometer, and a willingness to check your body everyday.

However, charting does require dedication on your part. It is necessary to record temperatures and changes daily; missing just one day can make all your other efforts useless for that cycle. Furthermore, none of these birth control methods offers you any protection from STDs, such as chlamydia. If you are concerned about contracting an STD, it is a good idea to use a condom.

Finally, women with irregular periods may want to choose other kinds of birth control, as charting may not be able to give you an accurate idea when you are fertile.