About time I got an answer.

Okay so. I've had this stuff come out of me two times and I've never really worried about it until now. I have PCOS and my periods are already pretty painful (like wanna go to the E.R kind of pain) when they have come out it's not just like blood coming out. It's actually pretty painful and I can feel it coming out. WHAT IS IT? The first two pictures are what happened this most recent time and the last one is the first time it happened. 
What is it? P.S sorry about the last picture being shitty