birth control
"I'm 18 and I've been on Microgestin for a little over a year now. In summary, it is a good contraceptive and it cleared up my acne, but it is completely ineffective at regulating my menstrual cycle. 

Although it is an effective method of birth control, my periods have been all over the place since I have been on this pill (and they used to be pretty regular) and I had a pregnancy scare a few months ago because I missed my period and only had some light brown discharge the week prior to when it was supposed to come. Ever since, my period has come 5-12 days earlier than it's supposed to. Because of this, I have no idea when I'm more fertile. I have never missed a pill but this still happens :("