Another broken budgie egg

Yesterday night I changed and transferred the couple budgies to a separate cage. I had prepared a better recessed bottom nest box. The 2 eggs where transferred without the sight of the birds since I turned the lights, and uses a leaf to touch and transfer the the eggs.
This afternoon, I saw another egg broken and empty at the bottom of the cage. I'm not sure whether  it's the 2nd egg or the 4th egg that was broken since I hadn't checked yet the numbers of eggs inside the box. It could be the 2nd or the 3rd egg that which empty shell was taken out by the hen.