A single line on a pregnancy test is considered negative for no pregnancy. However, the success rate of a pregnancy test is 75% and pregnancy cannot be ruled out completely. If you take the test too early, the results will not be accurate. The delayed or early menstrual period of one week is still within the normal range, we recommend relaxing, continue to observe, if you are not sure, you can carry out a blood HCG test, can be initially clear diagnosis. f