What Could The Unusual Vaginal Discharge Be?

This is going to sound strange. I have a cold and I am currently menstruating. So a little bit ago, I sneezed and blew my nose, and I felt something kind of wet in my pants. I went to check to see if maybe I needed to change my tampon, but there was this large... thing in my pants instead. I've seen the lining come out before, but this is very different than anything I've ever seen. It's about 8 centimeters long, maybe 3 wide, and it's a few millimeters thick, too. When I felt it, it was strange... slimy and kind of fleshy almost. In the parts not covered in blood, it is pinkish and gray.