We had one week a year from fifth to seventh grade, then ninth and tenth grade as well. We learned that sperm meets egg and makes a baby. Say no. Have sex and you'll end up having a baby that you'll have to either raise and watch ruin your life, give up for adoption and regret it for life, or have an abortion and be frowned upon by everyone you ever meet. Condoms were briefly mentioned as a possibility, but also that they can break and lead to the previous circumstances. I learned more about sex in AP Psychology than in "Family Life".
EDIT: STIs were not mentioned except for HIV/AIDs. Everything else I learned from the internet. Mostly Spammers. Woo.