how soon can a pregnancy test detect pregnancy

3 hours ago 3
Nature

You can take a pregnancy test as early as 6 days before your missed period with some of the most sensitive home pregnancy tests, which can detect very low levels of the hormone human chorionic gonadotropin (hCG) in urine

. However, testing this early carries a risk of false negatives because hCG levels may not yet be high enough to be detected by the test

. Typically, hCG starts to appear in urine about 7 to 9 days after ovulation, which is shortly after the fertilized egg implants in the uterine wall

. For the most accurate results, it is recommended to wait until the day of your missed period or later, when pregnancy tests are over 99% accurate if used correctly

. Testing with the first urine of the day is advised when testing early, as hCG concentration is highest then

. If you test too soon and get a negative result, it may be because the hormone levels are still too low, so retesting a few days later is recommended if you still suspect pregnancy

. Blood tests can detect pregnancy earlier than urine tests because they measure smaller amounts of hCG, but home urine tests are generally sufficient for most women

. In summary:

  • Earliest detection: about 6 days before missed period with sensitive tests
  • Reliable detection: on or after missed period with over 99% accuracy
  • Testing too early can lead to false negatives
  • Use first morning urine for early testing
  • Retest if negative but pregnancy is suspected

This timeline reflects that it can take up to two weeks from intercourse to a positive pregnancy test due to the time needed for fertilization, implantation, and hCG production