Now that I thought about it...how about this: 25 could just be the sensitivity of the test. Here, found something else for you from: http://babymed.com/FAQ/Content.aspx?13508 HCG stands for "Human Chorionic Gonadotropin", the pregnancy hormone. HCG is being produced by the placenta and enters the blood stream as soon as implantation happens, about one week after
fertilization and ...