The sudden rise in body temperature on the 8th day after ovulation does not indicate pregnancy, there is no diagnostic basis for this. After ovulation, the corpus luteum is formed locally, and the body temperature center rises under the stimulation of the corpus luteum, and the basal body temperature is around 37℃, which will last until the onset of menstruation, and a sudden rise in body temperature on the 8th day after ovulation cannot indicate pregnancy. There are many reasons for the increase in body temperature, it may be a normal increase in basal body temperature, or it may be caused by disease, such as upper respiratory tract infection, pneumonia, etc., which does not indicate pregnancy. If you have intercourse after ovulation, you can go to the hospital 10 to 14 days after intercourse to determine whether you are pregnant by taking blood HCG and urine pregnancy test.