Definitely check for fertility! Plus, you should add more so you don't have a lonely poult.

I have saved eggs up to 21 days before incubating with reasonable results. I know that 7 - 10 days is the recommended limit but...
@Sally Sunshine
has experimented with longer term storage of hatching eggs that shows reasonable results. My understanding is that you place the eggs pointy side up in a carton, place them in a plastic bag, store them in a cool place and do not turn them. It is worth a try.
Pointy side up, huh? And no turning. I could go for that. These ones I just hatched, some of them were over 10 days old. I just had them pointy side down on my counter with no turning. I dated them, too, and it was interesting to see that the one early quitter was dated the same day I set them. So freshest isn't necessarily the best.
I think I will save all of Swan's eggs and set them some time around my daughter's due date.
Finnie, eat that egg! And enjoy every bite!
LOL! I will just eat all of Muffin's eggs! She has been squatting for me the past few days, so I think she will be laying soon too. And she never squatted for Cinnamon, so I doubt any of hers will be fertile.