Thanks for writing to us.
There is nothing developmentally wrong with your child's milestones.
He could be a normal introvert nature of a Single Child .Sometimes single children are associated with a diagonally opposite behaviour of violent Stubbornness.
Kindly consult a Child Psychiatryst for an analysis.
I can understand your concern regarding your suspicion about "Autism" which is a complex developmental disability
affecting the socialising and communicating skills presenting itself within 03 years of life.The complex developmental neurological disorder presents with child showing uninterested in surroundings/non eye contact in a social setting/no interest in a social setting/less exchange of ideas /thoughts/feelings.
Kindly rule out a tendancy whether it could be a case of Autism.Even then, therapy is available.
Wishing you the very best,
Dr Lt Cdr ASN Bhushan.