Tmi possible plug picture

Andria
So I just went in to see if my waters broke. They did the swab test, which came back negative. Last week (34 weeks) I was "closed and firm" when doc checked my cervix. Today (35 weeks) I am dilated to 1. As I was leaving the office, I stopped to use the bathroom and this is what I saw when I wiped. Any clue as to what it is?