Eggs Dented?

[GexPex]

So I have 2 eggs that are currently denting in the incubator. They're at day 31. The 4 other eggs are not denting and the substrate still seems moist, so I doubt it's the moisture. One of the dented eggs was candled about 2 weeks ago with very good veins showing. The other looked like it was infertile.
Just wondering if this would be pre-hatching at this early in time? If so, why is the "infertile" one denting too?

I'm incubating at 83/84F in a homemade incubator made out of a styrofoam box, heat mat with thermostat, digital thermometer, bowl of water on the heat mat, and containing the eggs is a plastic pencil box with moist vermiculite.

 

[acpart]

I can tell you from my experience (though this won't really help you) that eggs denting can mean:
--going to hatch soon (though not at day 31 at 83 degrees)
--going to hatch in a few weeks but the egg will look nasty for awhile
--infertile
--dead in the egg

I've seen it all. There's not much to do but wait and try not to obsess too much (I'm in the same boat with more than 12 eggs that should be hatching, some of which are starting to dent and no idea what's going on).

Aliza

 

[GexPex]

*sigh* Well I hope it's not the latter two. Thank you for your response, though. I'm eager for these to hatch, but not this soon.

 

[GexPex]

Ok, now there's what appears to be a slight orange tint to the eggs. Seems to be on just the outside. Both feel rather soft compared to when they were nice and firm just 2 days ago. The outside seems to be rather moist (though no water has come in contact with the eggs except through moist...not wet...vermiculite). Is it getting close to hatching time? Or is this something to now worry about? Both the clearly fertile and seemingly infertile eggs have the same appearance on the outside now.