I forgot about the period talk. I never had one of those either. I learned everything I needed to know from my classmate, and close friend who started in the 3rd grade. She told mw everything I needed to know. I was still mortified when I started at 12, and did not say anything for some time. I eventually told my mom, and she was shocked that I did not bring it up when it happened. I had been told that getting your period meant you were a woman, by friends, and I was not ready to be a woman.
ETA: My friend really did do an excellent job explaining it to me. Her mom was an early developer, and worked in a medical facility, and did a brilliant job relating it to her. I understood the why's and what to do. With that said, if you are not having the talks, someone else is. :-/