I was having pains and cramps in my lower abdomen, i was on the pill. I have a 26 month old and a 9 month old. so i went to get checked out. pregnancy test at doctors office was negative, ultrasound a few days later showed "viable measuring 6mm". doctor told me to get off the pill, and 3 days later i started bleeding. pregnancy test still show negative, going for another ultrasound in a few days, please explain how one can bleed and not miscarry, and why a preg test would be neg but ultrasound pos?