Your basal body temperature is your lowest body temperature when you are at rest. It is typically measured after several hours of sleep. As soon as you are up and about, your temperature increases slightly.
his method takes a few months of daily tracking to establish the specific patterns happening in your body. Your body temperature changes slightly in response to hormonal changes related to ovulation. Before you ovulate, your body temperature is usually between 36.2°C and 36.5°C. The day after you ovulate, your temperature will increase by at least 0.5°C (36.7°C to 37.1°C for example) and stay at this temperature until menstruation. To use this method, measure and record your body temperature as soon as you wake up, after at least 6 hours of sleep/rest. This means taking your temperature before you get out of bed and before eating or drinking anything. Take your temperature at about the same time every day. If you like to sleep in on the weekend you might have to set an alarm!
You will need a special “basal body temperature” thermometer, available at drug stores. Some thermometers have a memory feature that records the previous reading so you don’t have to record it immediately. Be sure to record your sexual activity on the chart too. You will see the jump in temperature the day after you ovulate. Since you don’t see this change until after you ovulate, this method cannot help you time sex in order to conceive. However, it will help you determine if you are ovulating, how regular your cycle is, and how long your cycle is. It will also give you a good idea whether sex you had in the past was well-timed for conception. Remember, your most fertile days are the day prior to ovulation and the day of ovulation.
If your temperature doesn’t change over the course of your cycle, it is possible that you may not be ovulating. Get in touch with your health care provider.