How do you know when you is on your period?

Answer 1

Budgies are birds, not mammals. They do not have the same kind of reproductive cycle as mammals. Budgies do not menstruate or have periods. It's not like having an un-spayed female dog or cat that goes into heat occasionally.
Wild budgies are what are called opportunistic breeders. They will seek a mate whenever there are enough resources to support offspring. In captivity, a properly cared for budgie will always feel that she has enough resources to have babies. This is why it is important not to house budgies of different sexes together unless you are prepared for the possibility of chicks.
Even without being housed with males, a female budgie will sometimes produce an (unfertilized) egg. Budgies don't have the same genetics or diet as domestic chickens, and excessive egg laying can cause serious health problems including calcium deficiency and egg-binding. You should consult an avian veterinarian for more information about budgie reproduction.