Brown spots?

So I was suppose to start my period tomorrow.

I went to my grandmothers for dinner this evening and after i ate i started having horrible hot flashes, anyways when i come home I realized I looked like i had been bleeding and when i peed i had really light bleeding, with a couple little spot that where really dark brownish black colored and it wasn't blood.

Does any know what that could be?

I wish I would have took a picture.