HCG was 17 IU/L and could not be detected as normal on ultrasound. Shortly after the fertilized egg is deposited, the HCG level within the pregnant woman’s blood rises, doubling every day. If the blood test HCG is 17IU/L, the HCG level is very low, usually in the very early stages of pregnancy. Ultrasound is able to see the gestational sac, usually after 5 weeks of pregnancy, when HCG levels in normal pregnant women can reach thousands or even tens of thousands. So it is normal for HCG to be 17 IU/L and not be able to detect the gestational sac on ultrasound. It is generally not recommended that women check HCG too early, too early not only may appear false negative, false positive and other results, and the results of the reference significance is not very large. If the HCG is found to be 17IU/L, it is still necessary to repeat the test afterward, which will not only affect the mood, but also increase the cost of the test.