Pregnancy can be detected by delaying the menstrual period by one day, due to the ovulation period of the woman, which is usually 14 days before the next menstrual period. If you are pregnant at this time, the fertilized egg will secrete something called chorionic gonadotropin after 7 days of pregnancy, which can be detected in the blood on the 22nd day of the menstrual cycle. If your period is delayed by one day, that is, on the twenty-ninth or thirtieth day of your menstrual cycle. At this time, it can be detected not only in the urine, but also in the blood, unless there is no pregnancy, so a one-day delay in menstruation can detect pregnancy.