MaryZ, when that was me, I would have died of embarrassment too - but when I was 16 and actually sexually active, I would have remembered the conversation and come to my Mum for advice. I think. Certainly my Mum gave me advice well before I needed it, and it stayed with me and I was always responsible with contraception. And when I was accidentally-and-unwantedly pregnant at 19, I knew i could tell her and she wouldn't judge. So it might seem pointless right now, but it's really not. I knew what contraception was available to me and how to get it, and I also knew that if something went wrong, she wouldn't stop loving me.
Also, anyone with sons who is thinking "well the girl is to blame if she tells him she's on the pill" what the fucking hell are you teaching your boys about STDS? I mean, sorry, but that's a breathtaking abdication of responsibility, right there. Teach your sons to use condoms unless they're willing to stick with a pregnancy, because if they don't trust their girlfriend enough to believe that she's on the pill, they shouldn't trust her enough to believe she's not carrying an STD either. FFS.