eggs from same duck?

[pinkj009]

I got these 2 eggs about 24 hours apart. My pekins have just started laying. A total of 5 eggs now, including 1 soft shell.
I'm trying to determine if both are laying. I get 1 per day, so i would assume only 1 is laying. But there is a serious size difference. The pic doesn't really do justice.
Also, they eggs were layed in the same spot... for what thats worth.
Any help/advice wold be awesome. Thanks! !

 

[Amiga]

Could be from the same duck, especially if they are just getting started. You can dab a little food coloring on one vent and that will mark the eggs passed for the day.

 

[pinkj009]

The larger egg was a double yolk. And delicious. Still not sure if from same duck. I haven't collected any in a few days. They have either stopped laying, or hiding them really well. Haven't found a single egg since the large (double yolk) one.