I learned at home, I was probably in 4th grade. My parent's wanted to make sure I was informed and didn't get any bad information from rumors at school and stuff. My mom talked with me one-on-one and gave me some books (one of them was "It's Perfectly Normal", which I would recommend).
In middle school my sex-ed class was okay, but there was a lot of giggling and I didn't end up learning anything new. In high school my health class was terrible, and the only useful thing I got from it was CPR certification