Choosing The Test Level

I'm hoping to take the JLPT in Chicago this December, but I have no idea what level to test at. I've been studying on my own since late 2000. I'm mostly self-taught, with one community ed class and a few months of auditing a community college class. I consistently did well on the tests. (Real life [e.g., my job] got in the way of the class, though, so I had to stop attending.) Recently I started using Japanesepod101 intermediate level. It's got enough I can understand and enough new material to make it challenging.

I haven't started looking at it yet, but I have the level 3 questions and answers book for 2004-2006.

Thanks for any suggestions anyone can offer about what level I should choose.