It is possible to see or not see an ultrasound on the 38th day of pregnancy. These two cases are: the first case, can be seen is a pregnant woman with regular menstruation. For pregnant women with regular menstruation, the menstrual cycle is usually 28-30 days, and a urine test is positive on the 30th day of menopause. In this case, a gestational sac can be seen in the uterus under the ultrasound on the 35th day of menopause. In the case of pregnant women with irregular menstruation, the delayed ovulation and the delayed conception will result in the late development of the fertilized egg, so the urine test will be late and the pregnancy may not be detected until more than 30 days after menopause, and sometimes the urine test is positive only after 40 days of menopause. The gestational sac appears relatively late at this time and may not be visible at 38 days of menopause under ultrasound. Therefore, whether the gestational sac can be seen under the ultrasound on the 38th day of pregnancy depends on whether the pregnant woman is having regular periods, is ovulating normally and conceiving normally.