We first saw the paediatrician in May 2014. She took a full history and observed him and talked to him. His stimming (or tics or self stimulation or "movements without a purpose") didn't seem worrisome to her at all as it wasn't to me at the time either. To her he seemed fine socially and in every other way and at the time his stimming wasn't interfering with life.
She said she could send him for full assessment if I wanted (of course I'm kicking myself now) but I didn't feel it was necessary putting him through all that. So we were told to come back in 6 months at which point he'd be in Kindergarten then she could see how he was doing.
One thing she did help us with was to get him on a schedule for doing #2 in the toilet. He wouldn't listen to me but he listened to her so that was great and still works today.