If its small amounts and darker blood, and not combined with bleeding, take it easy and give your Dr. office a call tomorrow. If its bright red and a lot of it. And or combines with cramping, you might want to co.spider going into the er just so they can check your levels, and do an u/s to make sure everything's okay. Hoping for it to be nothing!
Depends if you are filling up a pantiliner or pad. Dime, nickel, quarter size???