I never sat down and actually had "the talk"
I learned a lot in school; and then once I got older my sister and I talked about it. I'm almost 16, and she's 21. So it wasn't awkward talking to her about it. My mom and I have a great relationship so I'm not afraid to just bring it up in conversation. If I have a question I know I can ask them. I think it's better knowing from your mom, and older sister (if you have one) then thinking you know everything about it, from things you learn in school. Chances are some of the things you hear, aren't true.