The newly formed fertilized egg is usually not visible under ultrasound, and the gestational sac is usually visible through abdominal ultrasound at about 5 weeks of pregnancy. When the sperm and the egg combine to form a fertilized egg, it has not yet been implanted, and it will take about 6-7 days before it can be implanted in the uterine lining. Moreover, when the fertilized egg has just been implanted, the gestational sac develops in a small way, and has not yet reached the size that can be seen by the ultrasound, therefore, the fertilized egg that has just been formed usually cannot be seen under the color ultrasound. Pregnant women can wait patiently for a specified period of time and then observe the size of the gestational sac through ultrasound and other examinations. Pregnant women during pregnancy should pay attention to do a good job of prenatal checkups, actively listen to the advice of professional doctors to do a good job of comprehensive care and health care, pay attention to more rest, at the same time should be relaxed, to avoid nervousness, anxiety, there is any discomfort should be timely to the hospital, by the doctor to clarify the diagnosis, and cooperate with the doctor to deal with the symptoms.