How long after the point of conception does it take for a pregnancy test to detect it?

About 2 weeks: In a person with very predictable, regular periods and a 28 day cycle: if you count from the first day of the last period- ovulation occurs on day 10, 11 or 12. Conception can therefore occur on day 10-14. The fertilized egg implants in the uterus a few days later. I know of examples where a urine pregnancy test was positive on day 24. Blood tests can be positive a few days before the urine test.

9-12 days: Pregnancy tests, which detect the presence of HCG (human chorionic gonadotropin), in your urine, are generally able to tell you if you're pregnant between 9-12 days after conception. That's the point at which the HCG concentration in your pee is high enough to be detected by the test. For some women, however, it can take slightly longer to detect a pregnancy.