Biochemical pregnancy does not need to be purged, biochemical pregnancy is in fact in the early stages of pregnancy, blood HCG laboratory test to confirm the diagnosis of pregnancy, but this time period is the time of the fertilized egg implantation, due to viral infections, drug damage, or radioactive damage and other factors, resulting in the failure of the fertilized egg implantation, did not continue to develop into a gestational sac, so that in the stage of the embryo is not yet formed on already! The pregnancy ends before the embryo is formed. It is also called subclinical abortion. If the blood HCG test is not done, it is actually equivalent to a delayed menstruation, and there is no residual embryonic tissue in the uterine cavity, so there is no need to clear the uterus, and the bleeding time is basically the same as that of a normal menstrual period.