If you are suppose to be 9 weeks and the ultrasound is showing six weeks with only a sac no fetal pole and no heartbeat, and bleeding it sounds to me like a miscarriage. It could also be you aren't as far along as you thought you were. did you doctor schedule you for another ultrasound in a week? If they did that is good they can check and see if anything does show up, if it isn't a miscarriage. Goodluck.
OMG sorry to hear. Same thing happened to me except I was cramping first and went to the ER and they did the ultrasound. Then the next morning it was when I finally had the miscarriage. If they cannot detect a heartbeat and the sac is empty, then you already miscarried. It just havnt came out yet. Same thing they told me. It really hurts to know but I hope the best for you. By the way, take some major pain meds like percocet and muscle relaxer and a motrin 800 combined. It wont kill you trust me, my doctor put me on flexiril, percocet, and motrin 800 and insisted I take them at the same time. It will ease the pain a lot a it will help with your uterus contracting. It also relaxes you and will help you sleep through it. Good Luck honey and sorry to hear that.