i first noticed my parakeets trying to mate about 5 days ago, and today she laid an egg in the nesting box. i dont want to shine a flashlight on the egg because i dont want to bother it too much. is there a different way i can find out if it's fertile? she's acting like it's fertile, she'll sit in the hole of the nesting box, while the male parakeet feeds her, and she makes baby parakeet sounds while he feeds her. if the egg was infertile would she still act like it is?

she's also been in the nesting box all day.