What Causes Abnormality In Pap Smear?

I am 27, female had a pap smear 2 weeks ago with my primary care physician. Results came back as abnormal, the type of abnormality in which i must follow up with a gynecologist. I called and they want to see me in 2 more weeks. The doctors wont tell me anything and most of what I have seen online says you go back in a couple of months when you get such results. Just as a generalization how worried should I be that they got me in so quickly.