Xamarin Forms to native & back query - ios

Question

Following is the navigation stack I have in my app
page 1 (forms)-> Page 2(Native IOS with Page renderer) -> Another IOS native view via UINavigationController (to select an image from photo galary & process it)-> Page 3 (forms)
Here is what I am trying to do:
Page 1 in forms: Click on a button
Page 2 in IOS using page renderer
Code:
protected override void OnElementChanged(VisualElementChangedEventArgs e)
{
base.OnElementChanged(e);
var page = e.NewElement as DummyPage;
AppDelegate.DummyPageRef = page;
var view = NativeView;
// create a new window instance based on the screen size
window = new UIWindow(UIScreen.MainScreen.Bounds);
viewController = new ImageViewController();
navigationController = new UINavigationController();
navigationController.PushViewController(viewController, false);
// If you have defined a view, add it here:
//window.AddSubview(navigationController.View);
window.RootViewController = navigationController;
// make the window visible
window.MakeKeyAndVisible();
//var label = new UILabel(new CGRect(0, 40, 320, 40));
//label.Text = "2 " + page.Heading;
//view.Add(label);
}
ImageViewController page in IOS opens a galary for user to select an image, processes the selected image & when done processing calls page 3 on Forms with following
Code:
var secondViewController = App.GoToPostScanPage().CreateViewController();
NavigationController.PushViewController(secondViewController, true);
This works fine. But when I see the page 3 on forms the backstack is still pointing to my dynamic page that I created to select & process the image. How can I get rid of this IOS navigation stack & jump back to my Forms Navigation stack? Is this possible?
Thanks
Supreet