If your period is very regular and is suddenly delayed, especially if it is delayed for more than 7 days, consider the following possibilities: 1. It is possible that you are pregnant, you can test yourself with early pregnancy test paper or go to the hospital to have a blood test for human chorionic gonadotropin, the most accurate blood test for pregnancy. 2. The most accurate way to check if you are pregnant is to have a blood test to see if you are pregnant. 3.