At different times in your life, your
menstrual cycle may become
irregular due to a variety of factors, including pregnancy, stress, diet, hormonal imbalance, exercise, and illness. (For more information, again, refer to our article on irregular periods.)***i got this off of womentowomen.com
so if you're cycles have been this long after stopping birth control, it is very likely, that this has become your "new" cycle....