Orientalis embryo, what stage?

[benjamin]

Well here's an egg that was laid on tuesday. It looks much different than the more recent eggs. The center looks like a white and black tennis ball. What is the name for this stage of development and in how many days do you think it will hatch. Here's a picture, unfortunately not a good one but you can just vaguely see the outline of the brown area against the white. I'll try and take some better pictures, not only of this one but of others showing the same traits.

 

[benjamin]

Here's a much better picture, to take it I needed to make my own macro "lense" and reposition the egg many times.