I had a period that started on October 9th and then received the Depo shot on the 1st of November. In November I didn't get a period and on November 19th I took a pregnancy test that came back negative. The passed couple of days I have been bleeding lightly and then this evening, I started having very bad cramping and the bleeding picked up. I passed something through my vagina that looked like a vein filled, thick, whitish membrane that was at least the size of a silver dollar. What could it be? A cyst? A miscarriage? Thanks for your help!

Optional Information:
Female, Age: 26, Idaho