Sweet and Sour Work

I am an associate working in a small general practice firm. I have been engaged in the practice of law for just over a year now. I am free to make my own hours and do not feel overworked. I have had the opportunity to work on many different types of cases. The only complaints that I have about my position is that I do not get enough guidance from my superiors.

The problem that I am having is that I do not enjoy the work that I am doing. For the past few months I have had the feeling that the practice of law is not for me. I am seriously considering changing careers. My question is: How long should I continue to practice law before I can be certain that it is not for me? Is it too soon, or should I just bite the bullet and move on?