Hurting and worried

Okay I was on the depo shot for maybe a year now and my period completely stopped but a month ago I didn't want to take it anymore so I stopped and well I think I 'started ' and it was just cramps same thing this month but what got me worried so much is thy my breasts started to produce a white milky substance ( I know normal breast milk is yellowish )  should I be worried about it !?! I'm freaking out