discharge or plug?

ak3627

So I am 37 weeks and was doing some nipple stim in the shower to try and jump start my labor (I have GD and do not want to be induced so I am trying things to get it started on my own).  I was having some serious contractions earlier this evening, so I was trying to jump start some more.  When I got out of the shower and was dry, a chunk of what looked like *** literally fell out of me...is this extra discharge from nipple stimulation or did I just loose part of my mucus plug?  The amount was about the size of a nickle.  ???