birth control
"I started taking Jolivette 6 months ago after I had my daughter since I was breastfeeding.  After 1 month and a half I was late taking a pill one day and the next day I started my period that last 5 days. Then the next month no period.  Than the next month I was spotting.  Each month as been different and unpredictable. I haven't had any side affects, besides the fact its a lot harder for me to lose weigh than with my first born. I don't know if the birth control is the cause but I'm guessing it is. The only negative thing about the pill is irregular periods and weigh gain."