The timing of the test varies depending on the method of measurement. For example, if a pregnant woman has a regular menstruation, it can be detected by urine test paper or blood test at the hospital after 3 days of menopause. The other is 10-15 days after intercourse, which can also be detected, and more than 15 days is more certain to be detected. Secondly, the method of measurement is different, you can test the urine HCG by yourself, or go to the hospital to test the blood HCG, the blood HCG test is very accurate, the value measured by both will be different. The blood HCG test is very accurate, and the value will be different between the two. The test can also be done by ultrasound, which requires a limited time and is relatively longer. If the HCG in urine or blood is not very high, such as 1000-2000 IU/L or 3000-4000 IU/L, it may not be detected by ultrasound. it is necessary to hold urine during ultrasound, including abdominal ultrasound and negative ultrasound, and generally the accuracy of negative ultrasound is greater. In short, as long as the menopause is more than 3-4 days, or after half a month of intercourse, it should generally be measured, only the time of measurement varies from early to late. Content source: Dr. You Lai