Pregnant Blonde 

There were three women sitting in a doctor's office, a blond, a 
brunette, and a red-head. They were all pregnant. 
"I'm having a boy because I was on the bottom," said the 
brunette. 
"Well, I'm having a girl because I was on top," said the 
red-head. 
All of a sudden the blond started crying. They asked her what was 
wrong. "I'm having puppies," exclaimed the blond.