Use Clearblue Ultra Early Pregnancy Test for results up to 6 days before your missed period (5 days before you expect your period) (1). Clearblue Ultra Early is our most sensitive pregnancy test (10mIU/ml) - no test can tell you sooner. It is over 99% accurate from the day you expect your period. For more information on this product or answers to your questions, our Careline advisors are available for you 07:00 – 15:00 hrs Mon-Fri, excluding Bank Holidays. You can also get more information about this pregnancy test at uk.clearblue.com. (1) ‘Missed period\' is the day after you expect your period. 79% of pregnant results can be detected 6 days before the missed period.