Good luck with your IEP. I have Asperger's Syndrome, didn't know till I was 43 and no formal diagnosis till I was 45. Up until the age of eleven my problems, related to this, were relatively minor. After eleven I figured I was the victim of an elaborate prank which got way out of hand, that people had a rotten sense of humor, certain people like to create drama with no real cause, but the things they maintained were wrong with me I knew were not true. I really believed I was the victim of schoolyard rumors and welcomed the opportunity to start high school in another state where no one in the school, students or teachers, knew anyone I did nor had any means of contacting them. This went so catastrophically wrong I didn't know whether to believe they were all just snots or I would have to give up on the schoolyard rumor theory and really consider something more sinister and paranormal such as a curse. I studiously took precautions believing I was under a curse for at least five years. (To be honest I've never completely stopped this.)
A diagnosis and IEP might have helped me in a few ways. One was, I had an extremely short attention span which got a hell of a lot shorter in Kindergarten. The teacher would explain something once, I'd be, fine, let's do it. Then she would explain again for the average kids. By the time she explained a THIRD TIME for the REALLY SLOW kids, she had totally lost me. I didn't even have to listen in school, or thought I didn't, until high school, and then only part of the time. By fifth grade I tuned so completely out I was basically not there at all. Every class was generally something I already knew (such as reading) or something in which I had no interest or aptitude (such as math or science). I thought I had eventually learned math (because I was better than I had been in school which was bloody awful) but when tested for my official diagnosis I came out as borderline retarded in math, as an adult of over 40! I was given remedial help or was assigned extra credit work in classes in which I was slow, but given little to no help to develop anything in which I was interested or good at. A few years after I graduated, the public school started an accelerated program to keep bright kids from not reaching their potential and dying of boredom. I don't know what the school does now.
Like many other people in my position, I wonder whether an IEP would have either helped, or held me back, as I would be singled out as a freak rather than as a normal kid who refused to do "right" when I supposedly "knew better." (In high school I would sometimes demand lengthy explanations from my peers, then the things they told me didn't make sense!) In the end I really don't know that it would have made any difference at all. I hope it proves of use to some people.