How long for "normal" menstrual cycle post mirena?

I'm 6 months post removal, thank God, and have concerns with my menstrual cycle. For the first 4 months it came regularly. Last month I began spotting on 33rd day with cycle start on 34th. Now I'm at the end of day 39 with no Aunt Flo. I don't believe I'm pregnant though I'll take a test to rule it out. I was just curious what everyone else's experience with this was. Any info is greatly appreciated. Thanks Ladies!!