The basal body temperature is always around 36.5 after ovulation, which may be a normal phenomenon, or it may be caused by poor follicle quality, inaccurate measurement of basal body temperature and other factors. 1. Normal phenomenon: the change of basal body temperature does not accurately indicate whether the body ovulation, and a small number of people even after ovulation, basal body temperature has no obvious changes, is a normal phenomenon. 2. Poor follicle quality: It may also be due to poor follicle quality and insufficient secretion of ovulation progesterone, resulting in insufficient basal body temperature response. 3. Inaccurate measurement of basal body temperature: Since the measurement of basal body temperature requires more strict requirements and there are many factors affecting the measurement of basal body temperature, it is difficult to accurately measure the value. To summarize, the basal body temperature after ovulation can only provide a certain reference value for judging ovulation, and cannot accurately indicate whether ovulation occurs or not, so it is recommended to go to the hospital for ultrasound examination to confirm the ovulation situation.