Sour got it right. But I’ll give you a bit more info.
It takes about 25 hours, give or take, for an egg to go through a hen’s internal egg making factory. That means if a mating takes place on a Friday, Friday’s egg will not be fertile. Saturday’s egg might be, depending on timing, but I don’t count on it. Sunday’s egg will be fertile. But note that this is after a mating. A rooster does not mate with every hen in the flock every day. Not with 11 hens.
But he doesn’t have to. The last part of the mating ritual is that the hen stands up and shales. This shake gets the sperm into a special container where it can possibly remain viable for more than three weeks. Most of us just count on the eggs being fertile for two weeks after a mating, however.
As Sour said, if they are not incubated they will not develop. As long as you collect the eggs once a day and store them where it is not hot, they will not develop.
If you do want to hatch eggs, collect all you want her to have and put them under her at the same time. That is important so they all hatch together. There are a lot of different ways you can go about having a hen hatch eggs once she goes broody. I mark the eggs I want her to hatch with a Sharpie and let her hatch them in a regular nest with the flock. I check under her once a day after the others have laid and remove any that don’t belong. These are fine to use as long as you remove them every day. I let her raise them with the flock too.
Others isolate the hen which she is incubating the eggs and and/or raising the chicks. There are all kinds of variations on these two. There is not just one right way where all others are wrong, it’s just how you choose to go about it.
Good luck!
