Hi there
I know it is very hard when you feel something is wrong with your child. I believe go with your gut instinct, if you feel something's wrong then most probably something is. Even though what you have described doesn't necessarily indicate Autism, it may indicate something else.
I'm having my daughter evaluated as she is demonstrating a few Autistic behaviours.
Some signs are as follows:
Flapping of hands.
Speech delays.
Resists cuddles/affection.
No or limited eye contact.
Doesn't interact in playtime (prefer to play alone).
Sensory Issues (dislikes some forms of touch).
Obsesses with unusual objects(may put the object very close to the face and seem to study it quiet intensly).
These are signs that my daughter is displaying. I know there are many more indications.
I absolutely believe you need to keep investigating the issue, one thing that my ped told me to is to record all of the unusual behaviour and take the recording to your next visit.
I hope this helps as I know exactly what it feels like to know something is wrong with your child. It's very distressing and a very emotional time.
Take care and I hope you get concrete results so that you can work to a wonderful future.
Julie