Could be wrong, but what I was taught in psych was that no IQ test is reliable past early childhood (ages 5-7ish) because then it starts testing knowledge and not intelligence. In fact, I believe IQ tests are meant to predict how well you'll do in school rather than how generally "intelligent" you are, and there are multiple theories of intelligence including ones about multiple intelligences (emotion, logical, natural, spatial, etc) and ones about general intelligences.
Basically I'm trying to say that IQ tests are pretty worthless in my opinion. Besides, imagine if you score very low or very high. Are you going to live your life any differently? It wouldn't make sense to do so.