beta-HCG levels can be detected in serum (from blood sample) around day 10-11 post conception; because the levels of this hormone double every 72 hours in a normal healthy pregnancy, it should be detectable in urine by day 12-14. read more
How early pregnancy can be detected depends on finding the hCG hormone. hCG can be detected in urine or blood after implantation, which occurs on average, about 9 days (range 6-12 days) after fertilization. Some home pregnancy tests claim to detect hCG as early as 4 days before the next expected period. read more
In fact, blood tests can detect the presence and levels of hCG as early as 8 days after conception. However, it takes a few more days for this hormone to appear in the urine, where the presence, but not the amount, can be measured with a home pregnancy test. read more