Discoloration on shells. Help!

[Camsmum]

I have never incubated eggs before, my ducks have always hatched them themselves. I have 5 call duck eggs that mum lost interest in after two weeks due to her deciding to follow another ducks newly hatched ducklings about. I candled them and they all looked viable.
I tried keeping them warm myself while I collected an incubator. I am worried they got too hot when I did this as the eggs felt very hot. I put them in incubator and they have been in there for three days now. However there is discoloration appearing on them. I have attached photos. Are they dead?

 

[333113]

Spots on duck eggs during incubation are usually not significant. Candling will tell you what you need to know.

If you are new to duck egg hatching, this is a good link:
https://www.metzerfarms.com/Candling.cfm

 

[Camsmum]

Thank you. Will have a look.

 

[Camsmum]

I can't get the link to load

 

[Camsmum]

What are all these dark bits?

 

[333113]

I can't get the link to load

You can search for "Metzer hatchery duck candling"--it's a US web site, if that helps.