THICK white rubbery tissue on tampon?

I started my period a few days early (today) and everything was normal (that including KILLER cramps) except two things:

First, my period has always started as a brown discharge that turns into a dark red period... but today, it started bright red. ( I know this may be minor, but i'm mentioning it just in case)

My main concern is when I wiped, the was a lot of thick rubbery, white tissue on the toilet paper everytime I wiped. I disregarded it at first, but when I took out my tampon, the majority of it was covered in a thick thick layer of this tissue. I could cut through it with my nail it was so thick. It's not mucus-like or a blood clot.

I've never had anything like this ever happen before and I'm NOT on birth control.