When to pick the right eggs from your hens to incubate?

[BarredRocks88]

I have been in the chicken buisness a while but only incubated once with the eggs of my own flock. I have 1 buff orpington, 6 barred rocks, and 1 rhode island red. (All Hens) The problem is I have recentley added a barred rock rooster to the flock, he has been with the hens for about a week now and he's already been breeding with the hens and they seem to like him. When should I save up the eggs from the hens that will be best to incubate? Thanks!

 

[Momo]

After the first three days your eggs should be fertile.