Getting on the spectrum

I don't know what prompted me to start researching Autism yesterday, but I know it has been in the back of our minds for almost two years.  With as much as you hear about it on Facebook, I was really surprised at the lack of information that is really out there, almost as if it is a mystery.  Aidan is such a happy boy, and I guess that isn't what comes to mind when you think about Autism, at least, not to my mind.  Part of me feels that I should just be grateful for the advances he's made, and that it would be insulting to other parents if I say that it's not enough.  I am grateful, he went from not even sitting up by himself or speaking at 20 months to now running and kicking, saying and signing a handful of words at 34 months.  I love him, and I would love him the same if this handful of words were all he ever knew, but I need to think about his future.  We will be homeschooling, but what if he is still eligible for services thru the school district?  What if he's not able to potty train?  What if he never gives up his bottle?  How do I handle his meltdowns?  His occupational therapist believes that he wouldn't have been able to make the advancements that he has if he were autistic, but I read that the earlier a child receives intervention the better off they are.  Could we have just started at a crucial point in his development?  His developmental therapist said she has wondered about certain characteristics and has even tested him in certain things on her own, and admitted as a mother she would get him checked.  We meet with his speech therapist tomorrow, she is young and the least experienced, but by far the closest to him and has made the most advancements with him.  While I have been doing research (not on WebMD!), I am not sure how far to pursue this.  In a lot of experiences I've read about, parents had a hard time getting a diagnosis for their child.  If I am persistent and demand a diagnosis, what damage am I doing?  Could it be just a developmental delay?  How will I know this if I don't accept that as an answer?  Do I wait months or years like the therapists recommended, or follow the online advice that the earlier the intervention the better?  And if I wait, could it get worse?  Could he regress when therapy ends on his third birthday?  Just about the only thing I do know is that we're not giving up.