I would say yes, 13 is way too young to be having oral sex. As Lorien said, some people are ready for it at that age, but most teenagers aren't. I know I would personally be shocked and upset if my 13 year old daughter told me she was being sexually active with her boyfriend.
I had sexual intercourse at 17, but I think I started oral sex when I was 16. We were careful with the oral sex, and we didn't start having intercourse until we'd been dating for over a year and I'd been on birth control (the Pill) for a couple of months.
If you are not ready to talk to your girlfriend about having oral sex, then you're not ready for sex of any kind. If you are not ready to talk to her about what she likes, what she's comfortable with, and what she wants to do with you, then you're not ready. Should you decide to have sexual intercourse together, if you cannot talk to her about it, if you can't talk about STD prevention and getting birth control to protect yourselves, you're not ready.
If you're happy talking to your girlfriend and hugging her, why not keep it there for now? Why should you rush to have sex at your age when things are happy and comfortable the way they are now? Sex doesn't automatically cement a relationship and make it better - sometimes it can make a relationship awkward, or destroy it altogether. Maybe it'd be better to keep your relationship the way it is now until you're both older.
3nodding If you're going to have oral sex, you can check out
this sticky. And if you want alternatives to being sexually active, you can take a look at
this sticky.
We can't stop you and your girlfriend from deciding to be sexually active, but we ask that you both think about it long and hard before you do. There's so much more to protecting yourselves and being careful aside from "getting a job and confronting your parents" if anything goes wrong. You need to do your research
before you do anything sexual together. There's lots of stickies in this guild, and the internet can be a great source of information too.