Pregnancy can be detected as early as around the 7th-10th day after intercourse. The methods to detect pregnancy include blood HCG measurement, urine early pregnancy measurement, basal body temperature measurement and ultrasound examination. The earliest positive sign of pregnancy is usually an increase in the concentration of HCG 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. If you want to determine pregnancy by urine early pregnancy, the earliest you can do so is 2 weeks after ovulation. Usually the above test cannot determine intrauterine pregnancy, so an ultrasound test is also needed at the same time. The gestational sac is usually visible on ultrasound examination 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 to determine pregnancy and diagnose common diseases in early pregnancy such as ectopic pregnancy and hyperemesis gravidarum. In the middle of pregnancy, that is, from 22 to 26 weeks of pregnancy, 4D ultrasound is done for teratology screening to clarify whether the fetus has any major malformations and major organ malformations. In addition, after conception, women’s body will show a series of special symptoms, such as menopause, vomiting, easy fatigue, etc., which can make the initial judgment on whether they are pregnant or not. For women of childbearing age, in good health and with a history of sexual intercourse, if the above-mentioned symptoms occur, pregnancy should be highly suspected, and it is recommended that relevant tests be performed in a timely manner to clarify the diagnosis.