Since each woman’s menstrual cycle is different, it may be normal to not see a gestational sac on day 42 of menopause, especially for women whose menstrual cycle is significantly delayed, which may delay ovulation and lead to late fertilization of the egg, so at this time, no obvious gestational sac can be seen in the uterine cavity during the ultrasound examination. However, for women who usually have a menstrual cycle of 28 days, or even an early menstrual cycle, it is often abnormal if no gestational sac is seen at 42 days. This is because in such women, on the 42nd day of menopause, a visible gestational sac should be visible in the uterine cavity, and even a fetal heart and germ should be present. Since the gestational sac is not visible at this time, the first thing to consider is the possibility of ectopic pregnancy. It is necessary to check the blood HCG and progesterone and to review the ultrasound to further confirm the diagnosis.