An invalid result on a pregnancy test signifies that the test did not perform as intended and the outcome cannot be reliably interpreted as either positive or negative. For example, the control line may not appear, or the test window may remain blank.
Understanding the factors that lead to an unusable test is important because it prevents misinterpretation and potential emotional distress. Addressing these issues ensures that individuals obtain accurate information regarding their pregnancy status, allowing for informed decision-making regarding reproductive health.