Basal body temperature is your body’s lowest resting temperature. We are going to explore when your basal body temperature drops if you are not pregnant, when it rises, what factors can affect it and more.
In this article:
- What is BBT?
- Why Should You Track Your Basal Body Temperature?
- What is an Implantation Dip?
- When Does Your BBT Change?
- How Do you Track Your BBT?
What is BBT?
BBT stands for basal body temperaure. Your basal body temperature is your body’s lowest resting temperature. To measure your basal body temperature, the only requirement is the purchase of an accurate thermometer.
Why Should You Track Your Basal Body Temperature?
The basal body temperature (BBT) method is a form of natural family planning. By tracking your BBT, you are able to predict ovulation, and even tell when implantation has occured by something called the implantation dip.
The basal body temperature (BBT charting) method can be used to best time when you should have sexual intercourse if you are trying to conceive, or on the contrary, if you are trying to avoid becoming pregnant.
Utilising the basal body temperature tracking method alone is not enough to reliably avoid conception, and it is usually used in combination with contraception or other methods of avoiding pregnancy.
What is an Implantation Dip?
The implantation dip is where the basal body temperature drops due to implantation- usually around one week after ovulation. This temperature drop usually lasts for one day, and can be considered a sign of pregnancy.
The implantation dip may be accompanied by- or precede by a few days- the following early pregnancy / implantation symptoms:
Whilst the implantation dip and implantation symptoms can be an indicator of pregnancy, the best way to be sure that you are pregnant is to take a pregnancy test.
When Does Your BBT Change?
We know that implantation can cause your basal body temperature to suddenly decrease for a day, by a few tenths of a degree, but when does your BBT drop is you are not pregnant? We answer this question- and other questions such as “When Does Your BBT Rise?”- by taking a closer look at how your menstrual cycle- and other factors- may affect your basal body temperature in the sections below.
When Does Your BBT Rise During Your Menstrual Cycle?
Your basal body temperature rises at two phases of your menstrual cycle: the ovulation phase, and the luteal phase.
Shortly after ovulation, your basal body temperature (BBT) rises to a few tenths of a degree. This sudden increase in temperature is due to the increase in progesterone production following ovulation. A rise in basal body temperature due to ovulation lasts for a few days (three days or more). You are able to identify this increase in temperature, which indicates ovulation, when you consistently monitor your basal body temperature.
You may experience the following ovulation symptoms, alongside the rise in slight rise in basal body temperature:
- Abdominal pain or cramping (ovulation pain)
- Breast tenderness
- Ovulation bleeding
- Changes in Cervical mucus
In order to confirm ovulation, you should take an ovulation test.
During the luteal phase- the period of time between ovulation and your menstrual period- the corpus luteum (the matured follicle in which the egg was released from), secretes progesterone for two weeks. This secretion of progesterone causes a slight increase in basal body temperature.
It is worth noting that your post ovulation temperatures can be an indicator as to whether or not you are pregnant: if your basal boy temperature stays risen, you may be pregnant.
When Does Your BBT Drop During Your Menstrual Cycle?
When you are not pregnant, your basal body temperature drops approximately one to two days prior to the beginning of your menstrual period. This is due to the drop in progesterone levels preceding your menstrual cycle.
What Factors Can Cause A Change in BBT?
The below factors can cause changes in your basal body temperature.
- Your quality and quantity of sleep
- Hormone levels
- Illness or infection
- Whether you have consumed alcohol
- Certain medication (for example, hormonal birth control)
How Do You Track Your BBT?
Basal Body Temperature tracking is a very useful form of natural family planning. By tracking your basal body temperature consistently for 2-3 regular menstrual cycles, you can quite accurately tell when to expect ovulation to occur, which can help you to time your sexual intercourse to conceive.
But how do you track your BBT correctly?
- Measure Your Basal Body Temperature. Every morning, at approximately the same time, you should use basal body thermometer, or digital oral thermometer, to measure basal body temperature.You should always try and aim for the same amount of uninterrupted sleep each night, and take your basal body temperature using the same method each time, to avoid external factors affecting your results.
- Record Your Results. You should record your daily temperature readings on a chart (either on paper or on an app) and keep an eye out for a pattern. This pattern can include temperature dips or changes at around the same time each month. Ovulation is indicated by a rise in basal body temperature.
- Take Action Based On Your Results. If you are trying to conceive, you should time your sexual intercourse for around two days before your basal body temperature rises.If you are trying to avoid conception, you should time your sexual intercourse outside of the period between the start of your menstrual period until four days after your basal body temperature rises, each month.
Hi, I’m Louise- mum of one to a little boy called Mason.
I am the Digital Marketing and Admin Assistant for MyBump2Baby.
I enjoy working to provide excellent service to MyBump2Baby’s growing families.
Nice to meet you!