For sufferers with obvious serum hCG concentrations above 15 to twenty IU/L, hCG must also be detectable in urine, whether it is actually elevated. Failure to detect urinary hCG in such patients, supports a false-positive serum hCG check. Pregnancy checks detect the hormone, human chorionic gonadotropin . After an egg is fertilized, the growing embryo attaches to the uterine lining approximately six to twelve days after ovulation. Following implantation, hCG is produced by trophoblastic cells…See More