The yolk sac is seen in early pregnancy and no germ is seen, this is the result of ultrasound monitoring in early pregnancy. From the development of the embryo to implantation, it is a different structure that appears with the continuation of time. Usually, only the yolk sac may be seen in the ultrasound before 6 weeks of gestation, and the embryonic bud and heart tube pulsation may not be seen yet, while the embryonic bud and heart tube pulsation may be seen after 6 weeks. If her menstrual cycle is regular and only the yolk sac is visible at 6 weeks without a germ, the quality of the embryo should be highly suspected and should be judged by monitoring the beta-HCG and progesterone values. If the value is low, the quality of the embryo is not good.