Whether HCG doubles at 6 weeks of pregnancy is related to the patient’s condition, some patients will double and some will not. HCG is the English abbreviation for human chorionic gonadotropin, which is a specific hormone secreted by trophoblast cells after the fertilized egg is deposited, reflecting the development of the embryo. If it is a normal pregnancy, the level of HCG will continue to rise, doubling every 1.7 to 2 days, and reaching its peak at 8 to 10 weeks of gestation, and the level of HCG at the 6th week of gestation in this case will continue to double. If the embryo stops developing, the level of human chorionic gonadotropin secreted by the trophoblast cells will gradually decrease, and the HCG level will not double in the 6th week of pregnancy; in the case of ectopic pregnancy, the fertilized egg is usually underdeveloped, the HCG level will be lower than the normal level, and the level will be increased slowly, and the gestational sac will have already been ruptured in the 6th week of pregnancy, and the HCG level of patients in the 6th week of pregnancy will not double. If the patient’s HCG level fluctuates abnormally, the patient should consult a doctor in time to clarify the cause of the disease, so as to avoid delaying the condition and leading to adverse consequences.