Swift 3 checking the WebView

I have my login page on the WebView

When i click the 'Log in' button on the site, it throws me to another page with different URL, which i need to parse

How do i check if URL changes?

Thats what i have:

   func displayURL(){


    let myURLAdress = "http://ift.tt/2l0Qj71"
    let myURL = URL(string: myURLAdress)
    let myURLRequest = URLRequest(url: myURL!)



        self.webView.loadRequest(myURLRequest)

   }