I am trying to find some meaning to the time it takes a dragon to breed and use that information to better guess what type of dragon egg to expect so I can prepare a proper habitat for it. 

I have so far bred 3 dragons: Moss, Flower and Lava. The Lava dragon is hatching now and I have a 4th dragon being bred right now. The Moss dragon took 12 hours to breed, the flower took 1 hour and the Lava took 10 hours. These times match the hatching times for the eggs as well.

Does this always stand true? Even for rare and limited dragons? The dragon I have hatching right now is taking 14 hours. This matches a Tree dragon's hatching time. Am I going to get a Tree dragon or do I have a chance of getting the Clover Dragon I want (which hatches in 7 hours).