Dragon egg problem - spots

[Jamisgec]

I have had my mountain dragon eggs in the incubator now for around 3 weeks. A few days ago i noticed them developing a spot on the top on the eggs. The spot in whiter than the colour of the eggs and has a red ring aorund it.

I have a hovabator incubator. It was air circulated but the fan broke inside.

Does anyone know what this could be?
(ill post some pics as soon as i can)

 

[JasonL]

Pics? though Mountains will hatch at room temp..