I Am Getting A Sinus Infection- Have Had It Before,

I am getting a sinus infection- have had it before, so I know the symptons. I have a prescription for Cephalexin - 4 pills, that I did not use prior to a surgery. Can I take these now since I am unable to see a doctor until next Wednesday? The mucus is green and the pain and pressure is building up in my right sinus.

YYYY@YYYY