Ten week ultrasound, no heartbeat, no signs of miscarriage.

I went in for my ten week ultrasound yesterday. I was suppose to measure at ten weeks and three days but the doctor found no heartbeat and the fetus measured at only nine weeks and three days. He said the baby passed away a week prior. I'm not showing any signs of a miscarriage. No loss of symptoms, no bleeding, no cramping. The fetus has been dead for a week now. Shouldn't I be lacking pregnancy symptoms? When will the fetal tissue pass? I have a lot of vaginal discharge, but I have throughout the whole pregnancy. Is there any chance this could be a mistake? If not, is this any cause for concern?
This is my fourth miscarriage and the past three times, I have shown symptoms of spontaneous abortion all before six weeks.
I am incredibly concerned. Something does not feel right here.