Early identification of an abnormal pregnancy is important. The diagnosis of ectopic pregnancy before tubal rupture can prevent life-threatening hemorrhage. This article provides a review of the normal development in early pregnancy and correlates this with ultrasound findings, followed by a structured approach to the ultrasound examination. The specific findings in early pregnancy are reviewed, and the predictive value of these findings in identifying either a normal or abnormal intrauterine pregnancy or an ectopic pregnancy are discussed.