Can a pregnancy be detected if the menstrual period is delayed by one day?

Generally, whether pregnancy can be detected one day after a missed period depends on the testing method used. A blood test measuring human chorionic gonadotropin (hCG) can usually provide a more accurate result, while a home pregnancy test using urine might not reliably detect pregnancy due to lower concentrations of hCG in the urine. Detailed analysis is as follows:

If a blood test for human chorionic gonadotropin (hCG) is used, even one day after a missed period, specialized equipment can detect changes in hCG levels, thereby accurately determining whether a woman is pregnant. This method has high sensitivity and provides more reliable results, making it suitable for individuals who want to confirm pregnancy as early as possible.

If a home pregnancy test is used, since one day after a missed period the concentration of hCG in the urine may not yet have reached a level clearly detectable by the test strip, a false-negative result may occur—meaning pregnancy is present, but the test shows negative.

To better determine whether you are pregnant, it is recommended to maintain a regular lifestyle after a missed period and avoid excessive fatigue and mental stress, which may affect hormone levels in the body. You can also choose an appropriate testing method based on your individual needs.