I got my period when I was only 11 and I was still a total child in my head. I knew about reproduction and periods, and I knew that I never wanted to have this awful period or at least only get them very late when I would be older.
When I noticed blood on my panties, I started screaming and crying and my mother couldn't calm me down. I was so paralyzed that it was my own mother who had to help me change and wash. I am embarrassed about it but I was simply too paralyzed.
My mother just told me "Congratulations, you can get pregnant." I do not think it is something you should say to a 11-year old girl who hates womanly traits on her body. My period triggered my anorexic behavior.
After that, every cycle I would have excruciating cramps that would keep me off school. I was so ashamed of bleeding, of "being a woman" and I still feel the same until now. It was a horrible experience. My flow was so heavy I frequently bled on school chairs.