Scene starts before scene loading is finished

So my problem is:

I have a loading screen to switch between scenes. The problem is that the scene starts before the loading screen disappear (music and coroutines).

I´m using this code for the loading screen:

public class ExampleClass : MonoBehaviour {
    IEnumerator Start() {
        AsyncOperation async = Application.LoadLevelAsync("MyBigLevel");
        yield return async;
        Debug.Log("Loading complete");
    }
}

Thanks in advance for the help!!

Async commands will cause your code to branch out right? so you’re loading side-by-side to your other code.