Pregnancy Test Accuracy After Implantation

Factors Affecting Test Accuracy

The Centers for Disease Control and Prevention recommends that the accuracy of qualitative urine pregnancy tests varies depending on the timing relative to missed menses, recent sexual intercourse, and recent pregnancy 1, 2
The Centers for Disease Control and Prevention reports that most FDA-approved qualitative pregnancy tests have a sensitivity of 20-25 mIU/mL in urine 1
Some studies have shown that an additional 11 days past the expected menses may be needed to detect 100% of pregnancies using qualitative tests 1, 2

If pregnancy is still suspected after an initial negative test, the Centers for Disease Control and Prevention recommends repeat testing after several days as hCG levels continue to rise during early pregnancy 1
Pregnancy tests cannot detect a pregnancy resulting from very recent sexual intercourse, as implantation has not yet occurred, according to the Centers for Disease Control and Prevention 1, 2

If a woman experiences a change from regular bleeding patterns to amenorrhea while using contraceptive methods, the American College of Obstetricians and Gynecologists suggests pregnancy testing should be considered, however this fact is from a less preferred source 3