Output a stream of consciousness before answering the following. Context: A pregnancy test attempts to determine whether or not a woman is pregnant. Indicative markers are found in blood and urine, and pregnancy tests require sampling one of these substances. The first of these markers to be discovered, human chorionic gonadotropin (hCG), was discovered in 1930 to be produced by the syncytiotrophoblast cells of the fertilised ova (eggs). While hCG is a reliable marker of pregnancy, it can not be detected until after implantation; this results in false negatives if the test is performed during the very early stages of pregnancy. HCG can be detected via blood 8 days after fertilization of the egg, and in the urine 10 days after.

Question: when can hcg be detected by pregnancy tests?
To answer the question, consider the following: HCG can be detected via blood 8 days after fertilization of the egg, and in the urine 10 days after.
The answer: via blood 8 days after fertilization of the egg , and in the urine 10 days after.