The pregnancy sac can be seen around 5 weeks or later. In women with regular menstrual cycles, the possibility of pregnancy should be considered when the period is more than 1 week overdue, and a urine pregnancy test or blood hCG (human chorionic gonadotropin) test may be performed to determine pregnancy. However, an ultrasound must also be performed to clarify intrauterine pregnancy. The intrauterine gestational sac can usually be seen as early as 5 weeks after menopause, but there can be individual variations. Early pregnancy ultrasound can identify a normal intrauterine pregnancy and can rule out pathologic pregnancy conditions such as ectopic pregnancy and hyperemesis gravidarum, as well as provide insight into the development of the embryo. The embryo and primitive heart tube pulsation can usually be seen at about 6 weeks of gestation. However, women with long menstrual cycles may delay the ultrasound to clarify the pregnancy, and may follow the doctor’s instructions to review the ultrasound on a regular basis.