Width of Screen

[Tarumi]

I'm creating my own toolbar that displays information across the top of my screen (like all the data brokers do). However, I can't get it to have my bar go across the entire top of my screen. It stops about 90% of the way across the screen.

This is what I have for the main frame:

local f = CreateFrame("FRAME", "Carrie", UIParent)
f:SetWidth(GetScreenWidth() * UIParent:GetEffectiveScale())
f:SetHeight(15)

I've also tried it with the * UIParent:GetEffectiveScale() to no avail.

Thanks!