The normal value of HCG in a blood test should be less than 5mIU/mL, which is a sign that the body is not pregnant. If the value is greater than 25mIU/mL and you have sexual intercourse without contraception, you should consider that you are pregnant. Chorionic gonadotropin is secreted by the cells of the trophoblast of the fertilized egg and has the function of protecting the gestational sac from the attack of the maternal immune system, with a high specificity. Pregnancy is basically diagnosed when a woman of childbearing age has sexual intercourse with cessation of menstruation and has an elevated HCG test. To be more accurate, you can see your doctor for an ultrasound examination if your period is more than 10 days overdue. If a gestational sac is found in the uterine cavity, you can be sure that it is a normal intrauterine pregnancy; a rise in chorionic gonadotropin alone does not determine a normal pregnancy.