First cycle after miscarriage.

I have always had 25 day cycles, and bled for 4-5 days max, during AF. I started miscarrying on September 15th, and I bled for 5 days. Everything happened naturally, and no medical intervention was needed. I was told to expect a normal cycle in 3-6 weeks. I started my first period on October 15th, meaning I had a 30 day cycle after my miscarriage, and I am still bleeding. My cycles have never been this long. My bleeding is still pretty heavy, and I'm still cramping like crazy on day 5. This is so out of my norm, that I'm concerned. Is it normal for a miscarriage to completely throw off your cycle pattern? Or to bleed so heavily still when a typical period would be ending? My body seems so screwed up. ?