I think sometimes you can take the questions wrong and read more into them, answering them falsely--that can give a result that isn't true. As happycheeks says, how you feel is most important.

That aside, I mentioned to a doc once that I was tired all the time. He had me take a 24 hour urine collection and sent it to a lab in TN or someplace--the only place at the time that did this test--and it showed I had low levels of brain chemicals and was probably clinically depressed. Of course, he also knew my family history--I have a sister with bipolar disorder and schizophrenia--so I was likely to have genetic-based depression. I've been on antidepressant medication ever since, about 30 years now.
So I think you can be depressed to a certain level and not realize it, based on my own experience.

Do read more on depression and see if it fits. If not, you are probably just fine.