Be CAREFUL. Use a condom.
As for the "speed" with which you moved from having never made out to "getting in her pants", all I can say is bravo.
People all move at whatever speed is comfortable for them. If you're moving quickly, that may just mean that you two feel very comfortable with each other.
Calm down. No one can suggest this enough. Stay calm, and things will be cool. Just enjoy yourself, and things will be best. Don't over-think things. Go slow.
Go slow.
Communicate with her. Don't assume that moaning/noises of pleasure means you're doing something exactly right, though it usually means you're on the right track.
Ask her how things feel. If she wants more, less, harder, softer, faster, slower... it's all good, and everyone is different. Listen to what she tells you, and you'll rock her socks off.
In short: Calm down. Communicate. Enjoy.
Oh, and most people's "first time" isn't all that impressive... the fun part is getting better and better, together, as you learn new things and explore each other further.