In the case of regular menstruation, the results of not testing for pregnancy when menstruation is delayed by one day are less accurate, and there may be a pregnancy, so there is hope. Generally speaking, for women who normally have regular menstruation, it is more accurate to delay menstruation for a week before testing for pregnancy. This is because in the early stage of pregnancy, the concentration of human chorionic gonadotropin (HCG) secreted by the embryo is increasing, and only when it reaches a certain threshold can the early pregnancy test paper detect it. Generally, HCG concentration is sufficient to be detected by early pregnancy tests only after a week’s delay of menstruation. If you take a pregnancy test one day after your period has been delayed, the HCG concentration may not be high enough, so there is a situation where the pregnancy test paper is negative but you are actually pregnant. In this case, you can wait for a few days, and if your period has not yet arrived, you can take another pregnancy test.