What Causes Dark Vaginal Spotting After A Laparoscopy To Remove A Cyst?

Hi, I had my right ovary removed 7 days ago due to a large cyst on it. It was done by laparoscopy. I also had my mirena removed at the same time and I am not presently on any other form of birth control. After my surgery I had some spoting until 3 days post op I started my period. It was heavy for 1 day then slowly decreasing until this morning I passed a few clots and the bleeding started again quite heavily. I dont have cramps tho. I fill up a pad in four hours twice. It is not bright red blood but dark period like blood. I was wondering if this was normal and how long I should expect to be bleeding.