Wondfo Early Result Pregnancy Test Detection is 99% accurate. It is at-home test for the detection of pregnancy. It detects the pregnancy hormone 6 days earlier than the day of your missed period. The concentration of the pregnancy hormone varies highly from woman to woman, so you can't make a general statement. In general, about 75 percent of pregnant women have a hCG level to perform a test up to 6 days before their period. However, if you test too soon you may get a negative result even if you're pregnant. Therefore, it makes sense to repeat the test in the next few days. When to collect urine for the test? Any urine specimen is appropriate for pregnancy testing but the first morning urine specimen is optimal because of its highest concentration of hCG. How to interpret the pregnancy test? On the pregnancy test, there are 2 lines, the control line and the test line. The control line must always be displayed, otherwise the test is invalid. If the result is positive, two colored lines appear on the test strip. It is important that the test line is about as dark as the control line. Note: This item contains 20 pregnancy tests strips. Do not use the test beyond expiration date. Our item has 3 years valid. The date of manufacture and expiration are shown on the package. Read the instruction before you test.