The time after pregnancy can be detected is related to the testing method and cannot be generalized. Generally, pregnancy can be detected about 1 week after intercourse by blood HCG test, and about 2 weeks after intercourse by urine HCG test. After intercourse, the sperm and egg will unite to form a fertilized egg, and HCG will be produced in the blood after 6-7 days, and the blood HCG value will rise around 10 days, and a mild increase in the blood HCG value can be detected by radioimmunoassay. In addition, after 35 days of menopause, a round or oval gestational sac can be seen in the uterine cavity by vaginal ultrasound in pregnant women. In addition, those who choose blood HCG test should take blood on an empty stomach, while those who use early pregnancy test paper should choose morning urine to detect pregnancy, which has a higher detection rate.