Pregnancy tests are over 99% accurate if taken correctly 1 week after the missed period. The 10-12 week information is not correct, especially for large numbers of women. I think smiliemama meant days, not weeks. Not all HPT kits are created equally. According to a study by The American Journal of Obstetrics and Gynecology, First Response Early Pregnancy Test is the most accurate. The others that follow are Clear Blue Easy One Minute and Clear Plan Easy. These three tests can detect extremely low volumes of hCG, the pregnancy hormone.