C# WPF MVVM Window OnLoad Binding

My Code behind looks like this...

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext = new MainWindowViewModel();
    }
}

My ViewModel looks like this...

class MainWindowViewModel : INotifyPropertyChanged
{
    public MainWindowViewModel()
    {
        bool flag = Application.Current.MainWindow.IsInitialized;

        if (flag)
        {
            // Do something...
        }

    }

I guess my question is....Does this conform to the MVVM design pattern? The only other way to do this is How to fire a Command when a window is loaded in wpf

I don't know why, but I don't want to use mvvm-light or any other boilerplate code..