No, you are not overbearing. You are smart.
Look. Let's say I don't want my kids to swim in the ocean without supervision until they're older. They don't know how to read the ocean yet, and can't deal with potential mishaps (like undertow/a cramp/rip tides). Do I still teach them to swim NOW? Of course. Educating them in water safety is not the same as allowing them to swim without supervision. My children are not ready to swim in the ocean by themselves, do it safely and deal with the (possible) repercussions. However, when they ARE ready, they'll know how to do it safely, and enjoy the activity.
Likewise, I don't want my kids on a roadway by themselves. My kids are still little, and when we're in town, they hold my hand near the road. I don't want them to be around cars without my help at this point. However, I still teach them how to take walks safely, because one day they WILL be old enough to cruise around by themselves...and when they are, I want them to know how to do so safely.
IMO, our kids SHOULD know what a condom is, how it works, and how effective they are at reducing the risk of pregnancy/stds. Our children should understand how to have safer sex. Knowing how to have safer sex, is not the same as promoting teen sex. It's simply gearing them up to 1. know ways to reduce physical risks 2. understand and respect consent 3. have respect for their bodies, their partner's body, and the act of sex.
Also, if we give our kids good information, they'll be able to share that, rather than half truths/rumors. In the case that a friend of theirs is having teen sex, they'll have the answers to questions like, "Do I need to check the expiration date of a condom? How do you put a condom on *correctly*? Does lube help reduce the chance of breakage? Can lube be petrolatum based, when using a condom? etc."
You've handed your son a great tool. And, you've talked comfortably and openly about sex. Guess what, he's more likely to come to YOU for advice! Fantastic job, T!