WHERE DO I COME FROM?

"Daddy where do I come from?" Bobby said 
Daddy went silent and his face turned red 
Daddy thought hard and finally replied  
"From your mummy's tummy you were nine months inside" 

"Thanks Daddy but how did I get there in the first place" 
Again Daddy went silent and went red in the face 
Thinking hard once again Daddy replied once more  
" Ask your Mummy Bobby because I'm not really sure"