Final answer:
Human chorionic gonadotropin (hCG) is detectable in maternal serum around 6-8 days after ovulation and in urine shortly thereafter, allowing early pregnancy detection.
Step-by-step explanation:
The hormone human chorionic gonadotropin (hCG), produced by the syncytiotrophoblast after implantation, becomes detectable in maternal serum as early as 6-8 days after ovulation, which corresponds to a few days after implantation. This hormone is critical for maintaining the corpus luteum and thereby ensuring the continued production of progesterone, necessary to support the developing embryo. ß-HCG is detectable via blood tests before it can be detected in urine, but within a few days post-implantation, it accumulates in sufficient quantities to give a positive result on a home urine pregnancy test.