Period late?

Ok, so typically my period comes a day or two early. It's never late. I suppose to come on my period today but there's no trace of it. Usually when I get my period I use the toilet then boom there's blood. Should I be worried because it isn't here yet? Also the week that my period supposed to come I be very moody and sensitive but I wasn't this time. That's the weird part about this whole ordeal.