There are several options that you can use.
1. When you create a page you can set it as navigable = false. Go to page properties and set Show in navigation to false.
|CmsManager manager = new CmsManager();
|ICmsPage Page = manager.CreatePage("Test");
|Page.Navigable = false;
2. You can use Sitefinity workflow thus the newly create page should be send for approval, approved and finally published.
All the best,
the Telerik team