How abnormal is the following for a woman?

Here is my situation: I was on the Depo form of birth control for 2 years and missed a shot due to the holidays. I got pregnant sometime around new years but didn't find out until the middle of march (when I started showing symptoms; morning sickness). I took a HPT and it was positive. I went to the clinic to make sure, and they confirmed my belief. I had an ultrasound done to determine how far along I was and discovered the fetus had already died about a month before. I decided to have a natural miscarriage instead of a D&G. For the next 9 months, nothing happened but occasional spotting. Last friday I began severly bleeding and pes a clot. I stopped bleeding after the intitial time. The following night it happened again in the same way. Then last night the same thing happened, but worse. Ever since last night I've been light headed, shaky, and naseus.