Pregnancy can be detected as early as around day 7-10 after intercourse. Methods to detect pregnancy include blood HCG assay, urine early pregnancy assay, basal body temperature assay and ultrasonography. The earliest positive indication of pregnancy is usually an increased concentration of HCG values in the blood. The HCG value in the blood usually starts to rise on the 7th-10th day after intercourse during ovulation, when the fertilized egg starts to bed down, and it is at this time that the pregnancy can be detected by measuring the blood HCG value. A urine test for early pregnancy usually gives a more definite measurement in 20 days. The blood test, on the other hand, can only be measured after at least 30 days, otherwise the concentration of progesterone in the blood is not sufficient and the result is not accurate. Usually the above tests cannot determine the intrauterine pregnancy, so an ultrasound test is also needed at the same time. The gestational sac is usually visible on ultrasound at 35 days of menopause, and the germinal bud and primitive heart tube pulsation are visible at 42 days. Ultrasound is usually done 3-5 times during pregnancy, once in early pregnancy, in order to determine pregnancy and diagnose common diseases in early pregnancy, such as ectopic pregnancy and hyperemesis gravidarum. In the middle of pregnancy, which is 22-26 weeks of pregnancy, 4D ultrasound screening is done to clarify whether the fetus has any major malformations and major organ malformations. For women of childbearing age, in good health and with a history of sexual intercourse, if symptoms such as menopause, early pregnancy reaction and frequent urination occur, pregnancy should be highly suspected and it is recommended to undergo relevant examinations for clear diagnosis in time.