What Causes Abnormal Vaginal Discharge?

This is really gross and I'm embarrased by it but it's never happened to me before. Yesterday I kept leaking fluids or something. It didn't smell and it's like water and I didn't even notice it until I was practically drenched in the stuff. I don't understand, it's been going on for a week. And for about two days it was red stuff instead of brown but then turned brown. Help me?