What Causes Orange Color Discharge During Menstruation?

I have had a 3 misscarriages over the last couple of years and am trying for a baby...since January I have had 28 days in my cycle until June and July which were 26 . Last weekend would have been my 26 days again and I did have a crampy belly and sore lower back for one day the next day nothing and no periord either...it got to day 33 and still no period or pain so I did a pregancy test which was negative. later than night I started to bleed but no pain and the blood is reddy orange? do you know what is going on?