Large white and red blood clot with major cramping

So I got the Depo shot about a month ago.  About a week after I got the shot I started bleeding, thought nothing of it, because I figured I was just started my period.  I have been bleeding for about 3 weeks now, with no break.  There were times when it would be lighter and then get heavier.  Yesterday, it was pretty heavy, and very dark red blood.  I had a very very mild cramping almost all day yesterday but nothing that I was concerned about.  Last night I started having pretty severe cramping.  I have had a past of issues and pain associated with ovarian cysts.  The pain last night was so intense that I thought I was having issues with my ovarian cysts, which hadn't happened in a very long time.  I finally got the strength to get out of bed and get into the bathroom because I felt like I needed to urinate.  When I went to the bathroom I had the dark red blood, and then I felt a strange sensation in my vagina.  I looked down and saw a very large...something...fall out of my vagina into the toilet.  When I looked after I got up off of the toilet, it was a very large (about 2 in. in length and about 1 in. in width)  blood clot, or what I figured was either a blood clot, a miscarriage, or maybe tissue that had built up because of the depo shot. Any ideas?


p.s. - The pain is very mild now.  After I passed it, the pain subsided, then got a little stronger, then I fell asleep.  When I woke up this morning, the pain was barely there.