What Causes Heavy Period With Cramps After Stopping Depo?

Hi, I use to take depo it ran out in January. I had a period in December an January, but that was the last I had one up until 2 weeks ago so I stopped on the 12 of June after 7 full days an it was brown colored the whole time. It started back yesterday, the day after I was suppose to be ovulating, it is a brownish to deeper red color an heavier than it was when I had it for a week and cramps are mild. What could this possibly mean?