Clearblue Early Detection Pregnancy Test for Results 6 days before your missed period, *'Missed period' is the day after you expect your period. In 79% of samples tested in a lab study, pregnancy could be detected up to 6 days before the missed period (which is 5 days before the expected period). Over 99% accurate from the day of your expected period Use Clearblue Ultra Early Pregnancy Test for results up to 6 days before your missed period. Clearblue Ultra Early is our most sensitive pregnancy test - no test can tell you sooner. It is over 99% accurate from the day you expect your period. ‘Missed period' is the day after you expect your period. 79% of pregnant results can be detected 6 days before the missed period.