Ortho tri cyclen

Britney
My period has been very crazy the last few months. It used to be like clockwork on the pill. Now it happens whenever it wants to. I have been on the pill for almost three months. I talked to my doctor and this is what he said " I don't think this birth control is effect for you any more, if your period doesn't regulate in a couple months we will switch your birth control" 
Has any one else had this happen?