Pregnancy can be detected by a two-day delay in menstruation. Regardless of whether a woman has regular periods or not, if pregnancy is suspected after a two-day delay, a blood HCG test can be performed to determine pregnancy. When a woman is pregnant, the blood HCG may double every other day and the progesterone value may gradually increase. If, upon testing, the HCG value is significantly higher, there are signs of pregnancy. If the HCG result is not elevated satisfactorily and the progesterone value gradually decreases, one needs to be alert to the possibility of ectopic pregnancy and preterm miscarriage. Women can also test their urine for early pregnancy, but since the fertilized egg has just been laid in the early stage of pregnancy, the concentration of HCG in urine is still very low, and if women drink a lot of water at this time, it will further dilute the concentration of HCG, so a false negative result may occur. It is recommended to use test strips to check the urine after 5 days of delayed menstruation, and it is better to choose morning urine to ensure that the composition of the urine is not diluted. In addition, a 2-day delay in menstruation may not necessarily be an effect of pregnancy, as it is normal for a normal period to be 2 days early or delayed, and there are women who have irregular periods that cause a delay in menstruation. Therefore, women are advised to test after a delay of 3-5 days to obtain accurate results in a shorter period of time.