There is some error in determining whether ovulation has occurred through the measurement of basal body temperature. Normally, the basal body temperature will rise during ovulation and gradually fall after ovulation, but it takes more than three months for this test to be accurate. It is especially difficult for women whose menstrual cycles are inherently unstable, and a non-rising basal body temperature does not mean that they are not ovulating. Therefore, for women who want to get pregnant, they should not rely solely on basal body temperature monitoring, and it is recommended to combine with ultrasound to monitor the size of the follicles to determine the time of ovulation, which is more direct and reliable. Of course, the success of pregnancy is related to many factors, only when ovulation, endocrine, immune and fallopian tubes and endometrium and other conditions are normal in order to get pregnant, so it is recommended to do a good job of all the pre-pregnancy checks and pre-pregnancy preparation to adjust the mindset.