A blonde, brunette, and redhead are each pregnant and at the doctor's office...

A blonde, brunette, and redhead are each pregnant and at the doctor's office...

While sitting in the waiting area, they begin chatting.

The brunette says "I was on the bottom so I'm having a girl!"
The redhead says "I was on top so I'm having a boy!"
The blonde starts crying hysterically.
The brunette and redhead ask her what's wrong.
The blonde says "I'm going to have a puppy!"