Question about my 2 day old duck egg!?

I have a 2 day old duck egg in my care - dont worry its in an incubator and its perfectly fine, im doing everything right! (my friend is away, but she is an experienced duck egg hatcher and she set up the incubator for me) Only, this is my first time as an 'adoptive mother' :) and im just wondering, if I shine a light through the egg, it is perfectly clear apart from a shadow on the opposite side. I know this is a good sign, but what im wondering is, is the shadow supposed to move or is it supposed to stay where it is, even if I roll the egg?