Please help

I don't have any pictures but my period was over a week late which isn't normal for me at all. I was beginning to think i may be pregnant but, today i got what i thought was my period and now I'm not sure. It started off really light and watery and reddish brown in colour, so watery my tampon wasn't catching it very well and when i went to change my tampon what looked like a long string of thick flesh fell out. It was pinkish grey and rubbery and extremely stretchy. It was as long as my hands and as thick as my finger. I've had clots before but this didn't look like a clot and I'm really hoping it wasn't a miscarriage... And now the blood is back to watery and it is pink. Has this happened to anyone and what did it turn out to be?