It's probably about being with the right person at the right time. It's not as if going out with someone should make you feel obliged to do certain acts, especially at your age.
You seem all to be more bothered with the act itself instead of thinking about who it's with. If you're not comfortable doing something with a certain guy then don't. Some girls seem to think that they have do certain acts with their boyfriend to prove they have a mature and serious relationship. Just do what you're comfortable with and wait till the right guy comes along.
I mean, guys have little respect for a girl who thinks "I have a boyfriend. That means I must go down on him."
It's not a requirement of a relationship to have oral sex. It's just one part of intimacy and foreplay, so don't feel required to do it, and certainly don't feel like "everyones doing it, I must be the only person not to".
Never do something you aren't comfortable with. Chat with your partner about it when you get to that stage in a relationship.
People talk openly about it because it, for them, isn't a big deal anymore, but you need to be able to communicate about it so you can begin to feel more comfortable with it..and being comfy with it doesn't mean actually having to do it.
It can be quite an embarrasing thing as it really is very intimate by the nature of the act, and this makes both boys and girls feel unsure of themselves. That's totally understandable, and many girls would prefer to give than recieve as they are unsure about their bodies (and men usually make us more unsure, because they are bloody useless).