Swift - how to check for existing Core Data Store iOS

I'm working on an app that should have a starting window that will have an intro and then either a "Get Started" button if no existing core data store is found, and then if a store is present - it should have a "Continue Session" and "Start Over" buttons. Only problem I don't think my code for checking for a store is working - I'm putting this in the ViewController's viewDidLoad function:

override func viewDidLoad() {
    super.viewDidLoad()
    let defaultStorePath = NSBundle.mainBundle().pathForResource("LearnUSStateCapitals", ofType: "sqlite")
    let fileManager = NSFileManager.defaultManager()
    if defaultStorePath == nil {
        println("can't find store")
        generateSCA()
    } else {
        println("store found...I think")
        continueButton.hidden = false
    }

So all I'm getting is "can't find store" - even after running the app a few times. I've navigated to \Library\Developer\CoreSimulator\Devices\blahblah\data\Containers\Data\Application\blahblah\Documents and do see my "LearnUSStateCapitals.sqlite" file there created at the time I first ran the app as is...

The reason I'm using "if defaultStorePath == nil" is because when I try "if fileManager.fileExistsAtPath(defaultStorePath!)" I get "unexpectedly found nil while unwrapping an Optional value" - why is this nil maybe the real question... thanks for any help