hCG or human chorionic gonadtrophin is known as the pregnancy hormone. This hormone is produced by the tissues that develop into the placenta as soon as implantation of the embryo occurs. Its other role is to maintain the other levels of hormones that are necessary to help the pregnancy develop. hCG is only detected if a patient is pregnant and will continue to rise as the pregnancy advances. hCG levels will double every 48 hours. Urinary pregnancy tests are highly sensitive and will detect the presence of hCG approximately two weeks after conception. We do not routinely test hCG levels via a blood test unless a patient experiences bleeding or pain very early into the pregnancy or if there is difficulty confirming the pregnancy via ultrasound.