Registering an IQ score beyond the age of about 6 is utterly pointless and proves nothing. If you've taken any psych classes, you should've been taught the Standford-Binet IQ test was created to help kids with mental disabilities get recognized quickly so they can be put into the appropriate classes with the attention they need. The Standford-Binet test is still generally what's used, and measures mental growth and aptitude instead of some level of acquired knowledge as most "IQ tests" on the internet do, which are totally bullshit and not worth a minute of your time. Thus, if you don't know your IQ by now and do not have it on file somewhere, you're not going to get an accurate measurement, so stop wasting your time.
For those of you who may disagree with me, I do have a BA in psych, and I've studied the subject of IQ tests before. Do a bit of research on the Standford-Binet test and see what you find.