I agree with
@Ruthless ...but I still wouldn't throw that egg way yet...it might surprise you.
Eggs in a batch can hatch at different times...even as long as a month later some will still hatch. It depends on the temperature it's incubated at so if the temperature in the incubator varies a bit from one area to the next, it can affect the hatching date. It's ok if that happens. I never throw an egg out unless it's absolutely 100% no good.
You asked ..."what are windows ?"... I showed you eggs with Windows ...look at the photo and you'll see that some areas of the eggs are white and some areas are more beige.
You said..."are mine about to hatch"... I would say not yet.