Day 7 egg candling

[BookWormDenise]

I bought 6 eggs from a breeder for my broody Silkie hen to sit on a week ago. I candled them and found only one to be developing (#1). Is there any way to tell for sure now if eggs #2-6 were fertilized or not? I candled with two different light sources and took pictures. Then I cracked each egg and tried to take a picture of the germ spot. All my amateur photos are attached. Thank you in advance!

Egg #1

Eggs #2-6 photos attached

 

[50-45-1]

I personaly never candle.
I think lots of potential chicks are discarded this way.
I've had plenty of eggs not hatch, but never had an egg explode in an incubator or under a broody.
Some of those deffinatly show progress to me.