As reliable as an ultrasound scan Clearblue DIGITAL with Weeks Indicator is the only test to date that is as reliable as an ultrasound scan at determining the week of pregnancy. For optimal certainty, the Smart Dual Sensor not only tells you in text form whether or not you are pregnant, but also tells you the week of pregnancy.* The advanced digital display means you don't have to waste time interpreting lines, so you get reliable, clear results even in the early stages of pregnancy. Benefit from over 99% reliability from the day your period is due. The only test that tells you how many weeks ago you conceived. * The display shows weeks since conception: 1-2, 2-3 or 3+, 93% accurate. Your doctor may date your pregnancy from the first day of your last period, not the day you conceived.