Pregnancy is usually not detectable on the 7th day of ovulation. When a pregnant woman has intercourse during ovulation, the sperm and egg will complete fertilization within 24 hours after ovulation. 6 to 7 days after fertilization, the embryo will lay on the ground and start to secrete HCG (human chorionic gonadotropin), and pregnancy can be detected by a blood HCG test at about 10 days after ovulation. After pregnancy is detected by blood HCG test during early pregnancy, it is necessary to confirm intrauterine pregnancy by ultrasound examination at about 6 weeks after menopause in order to exclude pathologies such as ectopic pregnancy and gravida. After early pregnancy is confirmed, it is necessary to follow the doctor’s instructions to take obstetrical examination on time, increase diet and nutrition appropriately, continue to take folic acid on time to prevent neural tube malformation of the fetus, and standardize the obstetrical examination under the guidance of the doctor.