Check If A RichText Box Is On The Bottom?

Is there a way to check if a RichText box is on the bottom? I don't think this is working:

Code:
If RichTextBox1.Selected = Len(RichTextBox1.Text)
'It's on the bottom
End If

What I am doing is, having the text go to the bottom (like a chat client) with this code:

Code:
RichTextBox1.SelectionStart = Len(RichTextBox1.Text)
RichTextBox1.ScrollToCaret()

However, if the user is looking at what was sent before, it scrolls them back to the bottom.