A childhood belief about reproduction

When i was about 5 years old, my mother would go to the doctors frequently b/c she was sick. My mother said she had to go to the doctor because it was a "woman" thing and i would understand later. But i came to a conclusion that everyone was born with a penis and In order to make girls, doctors would have to chop off the male's penis so the the baby could come out b/c the hole is bigger. i guess i was wrong...