HCG values in early pregnancy will gradually increase and double with the number of days of pregnancy, with values ranging from 9-130 mIU/L in the 3rd-4th weeks of pregnancy and 75-2600 mIU/L in the 4th-5th weeks of pregnancy, with the increase lasting until the 12th week and then gradually decreasing. If the number of days of conception increases in early pregnancy and HCG does not increase rapidly, consider whether the gestational sac is underdeveloped, whether there are signs of ectopic pregnancy and preeclampsia, you can do an ultrasound on the 42nd day after the menopause to make sure that it is an intrauterine pregnancy, and if the development of all the indexes is normal, and there is no abdominal pain, lumbar acidity, vaginal bleeding, etc., then carry out the routine pregnancy test in time, and conduct the Down’s syndrome screening in the 14th to 18th week of pregnancy, and 4-dimensional ultrasound test in the 20th week of pregnancy. 20 weeks for four-dimensional ultrasound testing.