It's great that you are so observant about your child. I think if you suspect something may be wrong, get your son evaluated. Most states have a program for testing for developmental/educational problems before age 3. First ask your pediatrician about your concerns as it is best if the pedicatrician makes the referral for you. BUt if you feel the pediatrciain is dismissing these concerns lightly (or taking too much of a wait-and-see approach), then ask for the info of your state's program and contact them yourselves (yes you can do this, and you shouldn't have a hard time - it's not too beaurocratic, at least not where I am).
Now, it's quite possible your son might be OK, and if that's the case, that's all to the better. But I worked with a woman whose son was eventually diagnosed with autism maybe around age 3 or 4. And she said after the diagnosis, the ONE thing she wished people had said to her when she'd experssed concern about her son, was 'Get him evaluated!'. Instead, other parents had told her 'oh, he'll be Ok, he's just following his own developmental schedule'. She said ultimately that the worst thing she did was to listen to that (unqualified) opinion. Early diagnosis is incredibly helpful for getting the therapy techniques the child needs.
Many parents tend to be in denial about anything they are seeing (my son was referred for evaluation and developmental intervention by the pediatrician at 1yr of age but I didn't realize anything was wrong!) So, while I don't want to scare you, I think that getting a specialized opinion is necessary, and I mean beyond that of your family doctor or pediatrician.
And like I said earlier, what you are seeing may not necessarily be autism... yet on the other hand it might be. If the *only* symptom he has is the rigidity to routine, that may be normal. On the other hand, there are plenty of autism symptoms that aren't picked up as actual symptoms by parents because they don't seem like a big deal (e.g. staring at lights or fans), so this is why involving a professional (at the very least, your pediatrician) so you can get a determination either way. Hope this helps and I really don't mean to scare you... just saying to take the steps to get a professional to decide one way or another.