They lay one egg per day. Never check the box in the morning, as that is when the hen tends to lay. She will not start incubating until all eggs are laid. Usually they lay 4-6 eggs. So perhaps if you check the box tomorrow afternoon, you will be surprised with another egg. Now that one egg is laid, did you put up the sparrow spooker? Make sure to get that done right away if you haven't, as that should help protect them from a HOSP attack.

Yep, like Kendra said Bluebirds lay one egg per day, typically in the morning hours, until the clutch is complete and then start incubation normally on the day the last egg is laid. Incubation lasts typically from 12-14 days and then hatching should occur. The nestlings are in the nest 16-19 days before they fledge. Please note that 13 days after the eggs have hatched, you should no longer open the box to check on them to prevent premature fledging. You don't want them leaving before they are ready and doing so could cause their death if they cannot fly well.

Check out sialis.org for loads of helpful informaion. I have put the link in for the sparrow spooker, you should get one up asap.

Good luck!
Donna

Here is a link that might be useful: Sparrow spooker