How many days of delayed menstruation are needed to test for early pregnancy?

Menstrual delay usually refers to when a period has not arrived beyond the normally expected time. For most women, the menstrual cycle is about 28 days, but it can vary from 21 to 35 days. If your period is a week (i.e., 7 days) late and you have had unprotected sexual intercourse, you can take a pregnancy test to check for pregnancy. However, some early pregnancy test strips can detect pregnancy as early as the first day of a missed period, although the results may not be very accurate. To obtain more reliable results, it is recommended to use a urine pregnancy test stick about a week after the expected start of your period or 10 days after a missed period. If the result is unclear or you remain concerned, it is best to consult a doctor or undergo a blood β-HCG (human chorionic gonadotropin) test, which typically provides a more accurate result.