Not sure if this is all that appropriate, but I used to think babies were born out of a women's... butt... and not their... you know...
I also used to think that you made babies by kissing.
A childhood belief about getting pregnant

others believed things like this
- I used to think that women had a secret door on their stomach that babies opened when they were bornAnon
- i used to believe that babies were made out of spit from people kissing too much, lol.— ecila
- When i was little I thought babies were made by french kissing. havn't you ever seen look whos talking now?!
— randa - I used to think that babies came out of the butt— Claire
- I used to believe that to make babies, a man would pee into a woman's butt. There. I said it.— Hu Flung Pu
- I used to believe that Labor Day was when all women had their babies!— Taralyn