Miscarriage.. Need Advice

I went in for blood work, an ultrasound and an appointment due to some light spotting(brown in color). I thought I should be 6weeks. The ultrasound tech said she saw the sac but it was too small to measure and resembled that of around 4weeks. After this I had my appointment(had to wait at least an hour after bloodwork to get hcg reading). The doctor told me everything looked fine and the ultrasound showed him exactly what he expected based off my blood work and that he believed I just ovulated late in my cycle. I went back two weeks later and my blood work came back fine. I had another ultrasound and this time they were able to measure the sac but couldn't see a baby. I was moved to another room and the doctor told me that I am miscarrying. I had three options...1. Let my body do things naturally, 2. Pills to speed along the process and 3. D&C. I chose to let my body do things naturally. This was on December 20th. It is now 8 days later and I am still experiencing morning(all day) sickness, fatigue, incredibly sore breasts and sore feet. I still feel 1st trimester pregnant. I go back in 5days for another ultrasound and bloodwork but very confused in the mean time. Is this normal to continue feeling pregnant even after the doctor confirms the pregnancy is non viable? When should I start passing blood and tissue? Is there any chance I might still be pregnant? Has this happened to anyone else?