Your BBT thermometer will come with a grid for you to chart your temperature on daily. You can also input your results into fertility apps such as Fertility Friend and Ovia.
By charting your BBT (basal body temperature) you can understand your menstrual cycle better and pinpoint ovulation. Each morning, before you get out of bed, you should take your temperature orally and chart it on the table. The graph will not be accurate unless you take your temperature the same time every morning. For the BBT reading to be accurate, you must have had at least 4 hours of uninterrupted sleep.
After ovulation, your temperature rises between 0.36 and 0.9 degrees F (0.2 and 0.5 degrees C). After doing about three charts, you should be able to recognise ovulation!
KEEP IN MIND; while using basal body thermometers is a very good way to home-track ovulation, it will only confirm ovulation AFTER it has occurred. Use in combination with Ovulation Predictor Kits for indication and confirmation.
More about Ovulation predictor kits HERE