Causes of bloody mucus in my nose and throat?

I have had a cold for about two week and things have gradually gotten better, so that now I barely have any symptoms. But, for the past three days I have had blood in the phlegm from my nose and mucus from my throat. Yesterday is was mainly bright yellow with only a little of blood in it. But, today when I spit out the mucus from my throat it was completely red and bloody. It was the texture of mucus, but looked just like blood. I am a littl worried because this happened three times today and I don't feel like that's normal. Any advice is good! Thanks!