Early pregnancy test strips have an expiration date, and if the expiration date is exceeded, the results detected with these test strips will be inaccurate, because after all, the test strips use certain chemical agents to understand the HCG level in urine, and if the reagent has expired, it will not play a corresponding role and cannot accurately understand the concentration of HCG in urine, so the results of pregnancy cannot be detected. When using early pregnancy test strips, it is important to know whether the package is complete and the expiration date, and it is okay to apply them within the expiration date, but if the expiration date is exceeded, it is not recommended to apply them and buy new test strips. In addition, when doing the early pregnancy test, you should also pay attention to the fact that if you drink too much water, it will lead to dilution of the urine, which may also lead to false negative results.