Okay I'm On My 4th Day Of Inactive Pills On

Okay I'm on my 4th day of inactive pills on my 3rd pack after having a baby 3months ago. The last 2paks my period has been super heavy and lasted the full 5-7 days now I have had very light pink bleeding not even enough tooo fill a tampon in a day and I take all my pills as directed what may be the reasoning I'm on mircett