My budgie laid an egg few days ago... can i disturb her to see if the egg is fertile?

i have a breeding pair of budgies, the female laid an egg about 5 days ago. last time i checked she had one, this was about 2 days ago. now the female frequently spends her time in the box while the male stands watch outside. can i disturb the female to check if the egg is fertile or should i wait until the egg hatches or until the female stops incubating?