What the heck is this

*****TRIGGER WARNING*******

So Friday morning this fell out of the shower. First thing I thought was a miscarriage.. 3 days before it happened I started bleeding lightly and the day before it got heavier, even the night before. I had my baby back in April and I've been on my birth control since June. I thought the bleeding was normal because my OBGYN said I'd have irregular bleeding possibly. We took it to my OBGYN and they don't even know what it is. They had to send it off to see the results. I won't know until Friday but it's bugging me so much on what it could be. Any other mommy's know what this could be?