Bloody discharge!? Help! Please!

Kayla
Aunt Flo came into town yesterday. It was a light period all day with mild cramps. 
I put a new tampon in this morning. Through all the craziness of today I kept forgetting to change it. I finally got home around 10pm (12 hours in) and there's barely anything. It's mostly a bloody discharge. 
Has anyone had this happen before?