They generally take care of the nesting box them selves. You just sit back and wait. It's amazing but they got it covered. The eggs usually hatch every other day once laid. Gestation for budgies is 18 days.

How to Know They Are Going To Lay Eggs.

I have budgies from 1 YEAR And till Now they dint lay eggs but Now i think They Are going to lay egg because the female budgie is spending a long time in the nest box and what should i bring for them to put in there nest box.