Four days of delayed menstruation and a negative urine pregnancy test suggest three main possibilities: First, the patient is not conceived. If the patient’s menstruation is delayed within a week, it belongs to a normal cycle fluctuation and can be temporarily left untreated as long as pregnancy is excluded. If the delay is more than one week, it should be considered as a temporary menstrual disorder or a menstrual disorder caused by other reasons, which needs to be diagnosed through gynecological ultrasound and endocrine examination. Second, consider that the patient conceived late and cannot be detected by urine pregnancy test for the time being. This is because the patient’s urine pregnancy test is not checked by the time of delay, but by the time of the last intercourse. It is more accurate to check the urine pregnancy test results after half a month after the last intercourse, and if the time is shorter, there may be a false negative result. Thirdly, false negatives occur due to the quality of the test strips used by the patient, or the testing procedure is not qualified. In this case, patients are advised to test again on the next day according to the specific requirements of the test, or go directly to the hospital to check the blood chorionic gonadotropin.