Popping page from Navigation stack

Hi,

Just a quick question about the Navigation stack. Say I have 3 pages, let's call them Page1, Page2, Page3. When I am on Page1, I press a button which Navigates to Page2 for a few seconds and then straight on to Page3 (Page2 is a loading page). However, when I am on Page3 and press the back button on android, it goes back to Page2. I want it to go straight from Page3 to Page1 on the back button being pressed. How would I go about popping Page2 off the stack after Page3 has fully loaded and is displayed on screen?

Thanks,
Mike.