[ponylady]

 ... but I'm still none the wiser 
Egg 1. Definitely developing,
Egg 2. Can't decide if it has an extremely thick shell, or if its infertile. Even in a totally black room, I can see nothing, not even the flaws in the shell.
Egg 3. Can't see anything, it seems empty, the shell isn't as thickens egg 2.

So I candled my other 2 eggs, which haven't yet been in the incubator, and I can see through the shell and make out the yolk.

Do I dump eggs 2 and 3 and replace with my spare eggs? Do I wait and see?
Decisions decisions, what to do what to do 

[Womble]

How long have they been in the incubator?

[ponylady]

This is day 9

[Kimbo]

candling CLB eggs should be easy so looks like you might be unlucky. You don't want one poor chick on its own either

[ponylady]

So difficult
Egg 1 is definitely ok
Egg 2 I am certain is infertile and I think I can see the yolk moving as I tip the egg
Egg 3 doesn't look like either egg 1 or 2.
I could ditch egg 2 and replace with another fertile egg but I am scared to do this in case I have got it wrong.

[Womble]

If you're not sure, leave it another few days.

I took to marking the ones I wasn't sure about at 10 days with a ? mark. I found that most of the time I was correct with my initial doubts, but it took a couple of weeks in the incubator to be sure I was making the right decision?

Can I ask why you're only incubating three eggs?  Is it because you only had so many, or is it because you can't fit any more in?

[ponylady]

My incubator only takes 3 big eggs, or 7 bantam eggs.
Any bigger and I wouldn't have enough self control and would hatch anything that's fertile!

[ponylady]

I've decided to stop worrying and just wonder! Will leave all eggs alone and wait and see in 11 days time
The suspense is making the days drag

[Kimbo]

but if you are right that means you will end up with a little solo chick and you will then have to find him/her a friend very quickly. Although you'd probably have to do that anyway now as your other eggs are 9 days behind