Bright spot in duck egg

[RoodyRodchester]

Have a duck egg on day 10. And during candling I noticed this bright spot. As the air cell grows the closer it comes to this spot. Is this something normal or will it cause a problem. Never seen it before in any of the other eggs I've incubated.

 

[JanetMarie]

It could be a thin spot in the shell. You could patch it with a small bandage, or superglue a piece of broken egg shell over it.