How soon is too soon

[ijustsawachickeneatafrog]

I have a broody incubating a batch of eggs (including 4 turkey eggs). I noticed the other day that 3 of the turkey eggs are starting to crack. They have another week before they're due to hatch. I patched them up as best I could with membrane from an egg out of my fridge and some glue (probably not the best way to do it, but it's all I had). I'm still worried though. If they hatch prematurely, will they survive? How soon can they hatch in order to live?
Thanks

 

[nuthatched]

Describe the cracking, like pipping? A line?
They could be that way from spoilage, did you ever candle them?

 

[ChickenCanoe]

Sounds like it could be a problem. What other species of eggs are with them?
If it is chickens and they were set at the same time, that is a problem.
Turkey eggs take 28 days.
What day were they set? Were all eggs set at the same time?
It takes turkey eggs 660-672 hours to hatch. Outside of that range can be a problem.

 

[ijustsawachickeneatafrog]

The cracks are lines, and I candles them this morning. The embryos inside were moving and very much alive.
They're with bantam silkie eggs, which were put under the broody a week or so after the turkey eggs in order for them to hatch at the same time

 

[Nigel27]

Chicken must’ve cracked them, I would say they were spoiled and about to burst but you candled them. Maybe the turkey eggs were thin and the chicken had a hard time turning them. Do you have and incubator?

 

[Nigel27]

And they can’t hatch even a little bit early or their yolk won’t be absorbed. Good luck, fingers crossed for you

 

[ijustsawachickeneatafrog]

Yeah, I had noticed they had what appeared to be weak patches in their shells the first time I candles them. I don't have an incubator, unfortunately.
Thanks for the help, I'm hoping they make it to term