When a pregnant Wyvergon transforms, so does her baby. But, a month before the pregnancy is over, she will stay in dragon form to lay the egg(s).

Another thing, is that the carrying period is much longer than average. Upon being conceived the child(ren) will be born a year and a half later. This long time is so that less development problems happen.
During development phases, females usually are more emotional (like a human) and they become very protective.
A month before the baby's expected birth/lay, the female, especially royalty, will flee from populated areas to nest.
Usually the only one to ever find them during the nesting period is their mate.
After the baby is laid, they will wait one week for it to hatch. After it is, the mother will take it back to the castle.