Is it tissue or is it mucous? Sometimes mucous can come out in clumps with little traily thingys, and it can look like some tissue, but really, it isn't.
In early pregnancy it is quite common to have excess mucous, as your body is trying to make a mucous plug. So I am just wondering if perhaps it isn't mucous instead.
I know the colour is troubling as well, but everything is engorged with blood, and things get easily irritated. Plus, implantation bleeding can start slowly coming out as well, causing things to look pinkish.
The other thing it could be, besides a loss, is a UTI. I had one once, that was so bad, there was blood visible in my urine, as well as some tissue that had degraded in my urinary tract, (I was 15 and had no clue what a UTI was, or that it was possible to get one, which was why I let it get to that point).
Please don't jump to conlusions yet. Take it easy, and do get checked out, but it may not be the worst possible scenario.