Ok, I can't seem to figure this out on my own so pleeeez help this SBM illiterate

Whenever I choose the page size that I want to put my design on and I get ready to print it out, there is always a small white edge all the way around my page or card. I always put my background as far out as my page size is shown on my screen but when it comes time to print, there is that edge.

In the past on my cards I have cut it off but then if I do this on my 8.5x11 page it will cut into my size that I need. Is there anyway to fix this problem?

Thank you