When I first heard about periods, I somehow misunderstood and thought that when you have your period, you pee out blood instead of pee. So after that I would always check the toilet for blood.
A childhood belief about periods

others believed things like this
- when I was young, I heard that blood had iron in it. I thought blood was red because it was rusty.— Hunter
- I used to believe period blood came from the nipples. I thought that was what "padded bras" were for!!Anon
- HA! I used to think when you got your period, you would just pee blood...I wish it was like that...if only.Anon
- I used to believe that guns shot out blood because everytime somebody shot a gun in a movie you saw blood.Anon
- when i was litte
I used to believe that white people had white blood and black people had black blood.Anon - I thought the blue veins in some cheeses were actually blood vessesls!— Helen