The temperature at which the implantation occurs is usually 0.3-0.5°C. The occurrence of a low body temperature is mainly caused by a significant drop in estrogen in the body. In clinical practice, the date of ovulation is determined by monitoring a person’s basal body temperature, and sexual relations at this time will greatly increase the chances of conception. For menstrual irregularities, the date of ovulation is difficult to predict. Significant temperature fluctuations occur when there is ovulation in the body, and the basal body temperature is bi-directional, while those who are not ovulating are uni-directional. This test is relatively simple, often convenient and effective, self-monitoring is completed. For a long time is not easy to conceive can use this method, but at least 3 months of continuous monitoring to have effect.