Can you see the pregnancy sac in the same room for 15 days?

Because women can only see the gestational sac after about 40 days of pregnancy, there is no way to find the gestational sac after 15 days of b-ultrasound examination. Because the female fertilized eggs are not well determined, so the time of B-ultrasound examination of the gestational sac is not well determined. Suggestions: If women want to determine their pregnancy, they can use blood tests to check.