The probability that the gestational sac has not grown in a week is not normal. The gestational sac refers to the primitive tissue of the placenta, which is the unformed state of the fetus, and generally, the gestational sac grows every day in early pregnancy. Under normal conditions, the gestational sac can usually grow 5-15mm a week, but everyone’s situation is not the same, according to a variety of factors to decide. Therefore, if the gestational sac does not grow in a week, then it is necessary to find out the reason. As the number of gestational weeks of pregnancy varies, how much the gestational sac grows each week will also vary, for example, around 5 weeks of pregnancy, the gestational sac may increase by around 5mm; around 6 weeks of pregnancy, the gestational sac may grow at around 12-15mm. If you notice any abnormalities during pregnancy, it is advisable to seek medical attention.