I'm on the mini pill (cerazette) and b/f dd (10 mths).
My periods returned with a vengeance last month with nasty cramping although not as bad as it was pre-dd, still in need of pain relief. Then after 7 days it stopped, but started again 3 days later, again with cramping etc. 7 days later it stopped and sure enough, 3 days after that another period, which I'm in the middle of right now.
So 3 periods in 21 days. 
I know you're told to expect "spotting" on the mini-pill but surely this is ridiculous!?