I am clueless about what caused my son's autism. I was a single mom in college when I had him so I do know that I was "required" to get all vaccinations when they told me because of my participation in programs like WIC, child care assistance, etc. I will tell you that he was developing fine and on schedule then all of a sudden everything stopped. As a first time parent my feeling was either this is terrible two's or something horrible is going on here. Almost right at 3 I went to a psychiatrist and he diagnosed him ADHD/Autistic. This was after he had been asked to "leave" a couple of child care centers. He is 11 now. I will also tell you that the fanaticism surrounding autism was not present back then. It was not as bad as the 50s or 60s but when I called the doctor later down the line to get the medical records with the diagnosis they refused. Nobody wanted to be the "bad guy" that scarred this child for life. In any case, my son was on several medications until finally in 2004 or 2005 I did not have the money and I said you know what we are going to deal with this. Through behavior modification and really his own self administered diet controls (somehow he knows what doesn't agree with him), he went on to get on the honor roll in an inclusive class actually and participate in a variety of social and athletic programs.
Every day is a challenge. He also only has a diagnosis of educational autism now because special education providers just did not see enough symptoms to label full autism. I will say that I notice little OCD type quirks in my own behavior and I wonder if it is something hereditary.
Definitely read read read, and my mistake was not keeping some kind of journal. Doctors will always ask you when did they start doing this? When did you notice that? And as new information becomes available about all sorts of subjects, you will want to have your records to come back to in the future.