So, home pregnancy tests will be accurate as soon as one day after a missed period for some women but not for others. So, the earlier after a missed period you take a HPT, the harder it is to spot the hCG. If you wait one week after a missed period to test, you are more apt to have an accurate result.
Why period is late?
Missed or late periods happen for many reasons other than pregnancy. There are also two times in a woman’s life when it’s totally normal for her period to be irregular: when it first begins, and when menopause starts. As your body goes through the transition, your normal cycle can become irregular.