Now you need to make sure they're stored safely to keep them as healthy as possible until you're ready, so that they have the best possible chance of hatching.
Let's make like a hen!
In the wild, a hen will lay several eggs before she starts sitting on them - sometimes as many as twelve. To her, incubating one at a time makes no sense.
So, as hens can only physically lay once each day, her clutch can be several days old before she begins to incubate.
What can we learn from a broody hen?
As with everything in hatching, our aim is to reproduce as closely as we can the way a hen will instinctively behave until she's ready to hunker down and start incubating.
Here are 5 pointers, learned from learning about chickens in the wild, watching my own hens, and my own experience in successfully hatching several clutches after transporting eggs from the UK to my coop in Italy.
One of the most critical issues for hatching is to avoid contamination with bacteria. By choice a hen will use a quiet, clean place to set her clutch.
If for any reason you need to store your fertile eggs for a few days before incubating, copy that instinct.
Although you won't be able to see it, bacteria can lurk in storage containers. Unless you're careful with hygiene, you run the risk of contaminating your current clutch.
If you're storing your fertile eggs in standard cardboard cartons, make sure they're new - don't use them for more than one set. Mark them "Fertile eggs - not for eating"!
If using plastic or resin containers, wash thoroughly before use. I use a baby-bottle sterilising liquid but a mild bleach solution is fine. Use one teaspoon of bleach to one litre (about one quart) of warm water.
A container like this one I use is ideal. It's strong, reusable and easily washed. After incubation it can be used to store eggs for eating.
A hen will keep her eggs lying sideways, and that's the way smaller incubators like the Brinsea Mini Advance (my favourite incubator) also work.
If you need to store them in a container like the one above, the eggs should always be stored with the more pointed end facing downwards, even if it's only for a short time. This makes sure the yolk stays properly suspended.
It's the way they should be set in the incubator, too.
If the more rounded end faces down for too long there's a danger that the air cell will become dislodged and the developing embryo will die.
My preferred option is to remove them from the upright container trays and lie the eggs on their side, protected by either kitchen roll or tissue paper.
It's how I transport them by car or plane, too.
She knows instinctively that she has to prevent the embryo sticking to the membrane inside the shell.
So we need to do the same.
A hen knows instinctively that an embryo won't start to develop until she sits on her clutch and they reach a specific temperature. So, until we're ready to begin the incubation process, we need to keep our own 'clutch' of fertile eggs cool and make sure they don't get wet.
This is really a question of balance. Wherever you store your eggs, their fertility will be best maintained if they're cool - but not too cold - and dry - but not too dry.
Look for somewhere in your house that's not heated and not humid. A garage or a dry basement or cellar is ideal, particularly if it's got a concrete floor. The ideal temperature is between 5º and 10º Centigrade (40º to 50º Farenheit).
Whatever you do, don't store them in your refrigerator - it's too cold and the air is much too dry. In dry air, eggs will lose moisture through the shell, particularly if they're small bantams or have particularly thin or porous shells.
If your chicks-to-be have arrived by post, or if like me you've carried them long distances, they will need to settle and come to room temperature before you set them in the incubator.
Allow them to "rest" for at least twelve, preferably 24 hours after arrival. Wherever possible, begin incubation immediately after that.
Advice about how long eggs will remain fertile varies. In reality, the longer they're left, the less fertile they become.
If they're kept in ideal conditions, some authors - Gail Dammerow, for example, in her wonderful book "Hatching and Brooding Your Own Chicks" - considers it possible that they will remain viable for up to three weeks.
When I've been driving to Italy from the UK with hatching eggs, I've had to keep eggs for as long as two weeks before incubating.
I've kept them in as near-optimal conditions as possible in the meantime, and hatch rates have been about 75% - 80%. It's obviously much better to incubate before that, though.
It's nearly time to incubate!
Before that, though, there are a couple more stages to go through: candling to choose the best quality eggs, choosing the right equipment and setting up your incubator.
The articles here will walk you through those steps.