Basal body temperature (BBT) is the temperature of your body at rest when it is measured in the morning after a minimum of three hours sleep. It is measured right after you wake up using a specialized BBT thermometer that you can purchase at any drugstore. The hormone estrogen plays a key role in the first half (follicular phase) of your monthly menstrual cycle where it helps the ovaries to produce an egg that is eventually released during ovulation. In the second half (luteal phase) of your menstrual cycle, the hormone progesterone dominates and maintains the lining of the endometrium until it falls leading to your menses.
To simplify things to help you understand, all you need to do is remember is that estrogen is “cold” while progesterone is “warm”. This means in BBT, before ovulation (the release of the egg to be fertilized) during the follicular phase, your BBT is relatively low. After the process of ovulation, your BBT starts to rise to the point where you can see a significant difference when you compare your BBT before and after ovulation if plotted on a graph. This concludes that if there is an increase in your basal body temperature, it means that ovulation has occurred.
What Is Basal Body Temperature Charting?
One of the best things about BBT charting is that there is very little required of you. The only thing you need is a reliable thermometer that can measure up to 0.10 degree as the changes in BBT can be quite small. You will also need a chart or graph that records your temperatures throughout your cycle. This is easily found online where it can be printed, or it also comes with a digital basal thermometer when you purchase one. You can even record your temperatures on a digital chart on your tablet, phone, or laptop. There are also BBT charting apps for your convenience. You may also download free software that enables you to keep track of your temperatures daily. Try it out here!
How Do I Get Started with BBT Charting?
Now that you have all the equipment you need, you can get started! As previously mentioned, basal temperature is the temperature you obtain the very first thing in the morning. This means that you must measure your temperature before doing anything else. Take your temperature before getting up, going to the bathroom, drinking water, etcetera. The emphasis is that it is the very first thing you do once you wake up and it has priority above everything else. Stick the thermometer into your mouth as soon as you wake up! The temperature should also be taken at approximately the same time every single day.
Start your BBT charting on the first day of your cycle. This is the day when you have your menses. Take your temperature and record it. The usual BBT before ovulation ranges from 97.0 to 97.6 Fahrenheit. Of course, every woman is different, and you don’t have to be confined to the usual range. Just take notice of the changes in the temperature every day and eventually, you will notice that your temperature is higher than usual. Generally, ovulation should have occurred when your BBT increases about 0.2 degrees higher compared to any of the temperatures from the prior 6 days and continues to stay elevated for a minimum of 3 days consecutively. The usual temperatures after ovulation range from 97.7 Fahrenheit or higher.
Will Charting Tell Me When I Am Going to Ovulate?
Using a BBT chart can only tell you once you have ovulated and unfortunately, cannot be used to predict ovulation. In some cases, there may be a dip in temperature on the day of ovulation, but this does not always happen with all cases. This dip in temperature is caused by the estrogen surge that causes ovulation. To predict ovulation, you can track your cervical mucus. The cervical mucus is the discharge that is produced by your cervix. It changes throughout your menstrual cycle due to the fluctuation of your hormone levels.
Tracking your cervical mucus and taking note of the changes can help to tell when you are at your most fertile. This can be done once your menstruation is over. With time, the cervical mucus starts becoming sticky and chalky. As you draw closer to ovulation, the fluid starts becoming thinner and the consistency changes to that of egg whites. This consistency is important as it allows the sperm to swim and travel through the cervix to reach the egg released during ovulation. During this time, you are highly fertile, and intercourse is encouraged daily once you start seeing the egg white consistency in your cervical fluid. You will also notice that your cervical fluid starts getting thicker or dryer after ovulation or the increase of your BTT.
There are some women who are able to check cervical mucous externally while some needs to do an internal examination. An internal examination is easiest if you sit on the toilet. One of the best times to check it is when you use the bathroom for the first time in the morning, but you can still check it at any point of time throughout your day. To get started, ensure your hands are clean and reach towards your cervix using your index or middle finger. Using both the BBT chart and analyzing your own cervical mucus is one of the best ways to assess your most fertile times. The most important rule is to have intercourse daily once you start seeing egg white consistency cervical mucus until there is an increase in your BTT. This ensures that you and your partner have intercourse on the days where you have the best chances of conceiving a baby.
What Are the Benefits of BTT Charting?
Once you start charting your BBT, you and your partner will most probably be able to conceive if both of you have normal fertility. The BBT charting and cervical mucus tracking allows you to know when you are most fertile. Remember that there are certain factors that may affect the appearance of your cervical mucus. This includes medications, intercourse, use of a lubricant, and douching.
BTT charting and cervical mucus tracking is crucial as the egg only survives for about 24 hours after ovulation. Timing is key! By charting, it also helps you to analyze your menstrual cycle. Although the general rule is that a woman ovulates on the fourteenth day of her cycle, every woman has their own patterns. This means ovulation can occur anytime between day 10 to day 21. BBT charting helps you to understand your body and your normal ovulation schedule. In case you have fertility issues, BTT charting can also help your doctor pinpoint the cause of it.
What Should I Do If Charting Does Not Work for Me?
Maybe charting does not work for you because you have a hectic lifestyle, or you just cannot seem to measure your temperature about the same time every day or it simply sounds too stressful. If you cannot make it work, there are still other ways that help to predict when you will ovulate. You can try an ovulation predictor kit that works by measuring your hormone levels and tells you approximately when you will ovulate. If you and your partner have a more flexible schedule, intercourse about every other day during mid cycle for two weeks may work as well.
Ovarian Predictor Kit
The commonest types are those that tests your urine for hormones that show ovulation is happening. Another type analyzes the salt content in your saliva as estrogen levels increase days before ovulation occurs. There are pros and cons to using an ovarian predictor kit. It is a convenient, simple, and easier way compared to BBT charting and cervical mucus tracking. However, it is also much more expensive as each ovarian predictor kit can cost between $20 to $50. The results can also be unreliable if you do not follow the exact instructions. Although it can be used to predict ovulation 24 to 36 hours before you ovulate, it does not actually confirm or tell you once you have ovulated. Ovarian predictor kits are only used a few days in the middle of your menstrual cycle as opposed to BBT charting and cervical mucus tracking that must be done every day. However, it may not work well for women with polycystic ovarian syndrome. If you are using fertility drugs, the results are inaccurate as well.