Android : getChildCount() returns 0 when called on TableLayout

This question is related to one I posted earlier. Views removed using removeView() are there when I next open the Activity (Android)

Background: When a user logs into my app they are taken from the login activity to the mainpage activity. The mainpage has a TableLayout that contains dynamically generated buttons. However if the user logs out and back in again, all of these buttons are repeated so I am trying to find out how best to remove these buttons after they are generated. In my previous post it was suggested I remove the buttons at the very start of the main page activity, before the new ones are drawn, so this is what I am trying to implement.

However when I call getChildCount() on this layout it does not always return the correct answer.

So far, here is the code that is run at the start of the main page activity:

        TableLayout tableLayout = (TableLayout)findViewById(R.id.MainPageTableTitle);
        //removeSectionButtons(tableLayout);  this is where i am trying to remove the buttons
        System.out.println("there are  oncreate " + tableLayout.getChildCount());
        drawButtons(tableLayout);
        System.out.println("there are  ondraw " + tableLayout.getChildCount());

The first print line returns 0 and the second print line always returns the correct answer (number of buttons drawn including all of the repeated ones). But I am not sure why getChildCount() returns the wrong answer the first time. If anyone can explain I would be incredibly grateful