The accuracy of HCG test is high, especially blood HCG test is more accurate, but due to various factors such as the testing method, testing time and physical condition of the testing population, the accuracy can also have some errors: 1. The level of HCG in urine is relatively low, while blood HCG is more sensitive and not affected by female diet and other factors, and it is a specific test, but early pregnancy test paper may be out of date, quality problems, etc. Therefore, HCG testing by blood sampling in hospital laboratories is more accurate than early pregnancy test paper; 2. It is not recommended to carry out emergency HCG test, because the time of emergency HCG test is shorter, so it may cause a larger error in the test result. Second, the detection time: some women are pregnant too short, the detection time is too early, resulting in HCG test results may be false negative, usually 10-14 days after sex can detect HCG, the results are more accurate. Third, the detection population: 1, gynecological diseases: some women detect urine HCG through early pregnancy test paper and other tests to determine whether they are pregnant, but women suffering from premature ovarian failure, endometrial disease can have abnormal HCG values. In addition, women with ectopic pregnancy have lower HCG levels, so it is recommended to recheck HCG again at an interval of 2-3 days; 2. The effect of drugs: a few women may have used HCG drugs to promote ovulation due to abnormal ovulation, and the drugs are not completely metabolized after use, and the above cases may show false positive HCG during the test, while there is no actual pregnancy. HCG test is commonly used in clinical practice for early pregnancy, ectopic pregnancy and The HCG test is commonly used in clinical practice for the diagnosis of early pregnancy, ectopic pregnancy and incomplete abortion, but the diagnosis of early pregnancy should be combined with ultrasound and clinical symptoms to be more accurate. If a woman’s HCG level is elevated and accompanied by menstruation, she has a higher probability of pregnancy.