Disclaimer: I use CC2, not CC3, but this should still be accurate, I hope.
It sounds to me as if you have your bmp on the same layer as the stuff you traced. In order to show that and hide the new, or vice versa, it does need to be on a separate layer, but you don't necessarily need to create one (although I usually do).
To do so, use the Change Layer command (CHANGEL), select the bmp, right-click and choose Do It. The prompt will ask for a layer name; if you right-click it will bring up a dialog. Select (or add and then select) a layer the pic can have all to itself, and click ok.
Now your pic and your drawings should be on separate layers so that you can hide and show them (freezing the pic is usually very helpful as well) to your heart's content.