Usually a successful implantation of a fertilized egg can occur after the implantation cooling, which can occur as early as day 7 after ovulation and in most women on day 8-10 after ovulation and lasts for about 1 day. Usually, the transition from low to high temperature can occur after ovulation, and the high temperature period lasts for about 12-16 days. A sudden and transient drop in body temperature can occur during this process, suggesting the successful implantation of the fertilized egg, i.e., implantation cooling. However, this is not a drop in body temperature, but only a relative low temperature state. In addition, it takes about 1 day for the sperm and egg to unite, and on the 6th-7th day after fertilization, implantation of the fetus begins, so the temperature at implantation mostly occurs 8-10 days after ovulation. The usual cooling range of the temperature at implantation is 0.5°C. Due to individual differences, not every pregnant woman can have a cooling temperature at implantation. In addition, a small number of women may experience mild abdominal pain and a little vaginal redness during the process of fertilization, which is normal and not a cause for concern.