An egg takes about 25 hours to go through the hen's internal egg making factory, from when the yolk is released to start that journey until it is in the nest. That egg can only be fertilized during the first few minutes of that journey. That means if a mating takes place on Monday, Monday's egg is not fertile. Tuesday's egg might or might not be, depending on timing. Wednesday's egg should be fertile.
This is after a successful mating. A rooster does not necessarily mate every hen in his flock every day, but he doesn't have to. In the last part of the mating act the rooster hops off, his part is done. The hen stands up, fluffs up, and shakes. This fluffy shake moves the sperm to a storage container near where the egg starts its journey. That sperm can remain viable for over a week. In some cases it remains viable for over three weeks. With living animals you don't get guarantees on things like this, it can vary by the individual. If you want to clean out a hen it's probably best to keep her clean for a month from a specific rooster. If you want to assure she is laying fertile eggs and you can't house the rooster with the hen I'd be OK with two weeks but would prefer even less. I don't know what your set-up is but I'd probably set up a weekly rotation, same day every week, just to avoid confusion. The older I get the easier I am confused. Was that last week or two weeks ago?