INTJ or INFJ

I wanted to ask the group about this.  When I first took the personality test (it was kiersey.com online test) it said I was actually INFJ.  But then I took the test two more times and it said INTJ.  Is it possible that I am borderline where I exhibit behaviors from both personalities?  Or do you think the first one was a fluke?  I seem to have some of the behaviors of INFJ but some of INTJ as well. 

I'm confused! Is there a better test I can take?