Is it possible to have a miscarriage and still be pregnant?

Yes, but...: A woman would have to start out with twins (or triplets). Then, one baby fetus dies, and the other one keeps growing. It's called Vanishing Twin syndrome when 2 babies appear on an ultrasound scan, and then there is only one baby on later scans. If the pregnancy is very early, or if one hasn't even done a pregnancy test, one can just start by doing a home pregnancy test.