Please refer to the Blue bird Forum, where you may receive a swifter answer.

Here is a link that might be useful: Bluebird fourm

Thanks, I am new to this site so I am learning my way around

Baker, I can think of two possibilities. One is that they have not started incubating yet. Bluebirds can lay up to 7 eggs. Once the eggs are in the nest, the incubation does not need to start right away. Also, the mother may leave the eggs for longer periods if it is hot out. Another possibility is that you have a wasp nest in the box. They will abandon nests where wasps have set up shop. Check on the roof for a wasp nest. To avoid this, always rub paraffin wax or soap on the roof of the house. Or you can rub a thin coat of vaseline on the roof and about 1/2 inch down on the sides. You should be sure to wipe this out well with a paper towel leaving a very thin coating. Ideally this should be done in the early spring before the nesting season, but you could still do it now.