Day 28 with ducks no pips

[Cjsights]

Hi one of my eggs started looking bruised a few days ago now day 28 has this bubble ? Any ideas what it is ? Day 28 and no pips in any of my 12 eggs

 

[JaeG]

I have only incubated Muscovy ducks, so I'm no expert, but I had one die just before it pipped internally and it got that bruised look. I would remove that egg carefully and dispose of it, especially if it has started to ooze.

There's nothing to stop you candling the other eggs if none have externally pipped. Your temperature may have been on the cool side, delaying them a little. You are looking for shadows in the air cell (fat end of the egg) and if they have pipped internally you should see the ducklings beak.