What to do?

NOTE: WE ARE NOT PREGNANT! WE DON'T INTEND TO BE FOR SOME TIME!
For the past 3 weeks Mikey has been obsessed with having a baby sister. He brings it up whenever he can. He is, however, willing to accept a very specific blue bird in a white cage instead of a baby(I don't know why he is so specific or why he wants a bird...or a white cage) and he wants to name said bird, "Bluey". We have a fish named Azul. As you can see, 3 year olds aren't creative in the naming department. Here are some comments in regard to the wanted baby sister.

After I picked Mikey up from school last week:
Mikey:When is this going to happen?
Me: When is what going to happen?
Mikey: When is Daddy going to put a baby in your tummy?

When playing in the backyard on Monday:
Mikey: Mommy, will you hold this (he approached me with his arm cradled and an invisible baby)
Me: What am I holding?
Mikey: My baby sister, I can't hold her and ride my scooter. I am going to town to a restaurant with my friends.

When playing blocks with Scott:
Mikey: Daddy, can you be my brother?
Scott: No, I'm your daddy.
Mikey: Well ,how about I just have a baby brother?

When just watching tv:
Mikey: When is my baby sister going to get here?
Me: I don't know if that will ever happen. Where would your baby sister sleep if we had one?
Mikey: In a baby bed.
Me: Where would the baby bed go?
Mikey: In my room. It's where the kids sleep.

When I asked him about the bird this is what happened:
Me: Where will the bird sleep if you get one?
Mikey: In his cage,
Me: Where would his cage be?
Mikey: In my closet.

My kid cracks me up.