The accuracy of blood tests to detect pregnancy is very high and can reach over 90%. Chorionic gonadotropin rises in a woman’s body when she is pregnant. If a woman is pregnant, as long as she insists on monitoring the chorionic gonadotropin level, she will find that the rise in chorionic gonadotropin is very good, and she can determine whether she is pregnant by taking a blood test for chorionic gonadotropin, and she can find out the viability of the embryo. If the HCG doubles well, it indicates good embryonic viability, while a bad doubling or no doubling at all, it indicates possible preterm or indolent miscarriage.