3.5 yr old boy Autism?

Hi, Our 3 yr old son (youngest of 3 boys) was born 5 wks early and stayed in the NICU for 10 days at birth.  He's been advanced in his development reaching all the milestones. He's never been a great sleeper usually waking up if he's uncomfortable at night and sometime it's tough to get him back to sleep. He also wants to hold our finger and draw on our thumbnail to sooth himself to sleep at night.  He used to eat anything but in the past year he's become picky to a point where he just is to busy to eat.  He just started Montessori School and we had a conference after a month at the program. The teacher didn't say to us he's Autistic but recommended we talk with a Dr. about him. She said he's very quiet around the other kids and after spending the last four weeks going over #'s with him he still can tell the #'s from each other when she looks at him he looks like he's giving her a blank sign on his face and then he starts blinking his eyes really tight. If they ask him to walk 5 steps and get something off the shelf he'll be all the way at the other side of the room like he didn't hear them or just didn't understand what to do. He also brings his lunch to school and rarely eats it. Not to mention he doesn't even attempt to open his lunch box with out assistance. She noticed that he eats his apple everyday in a circular motion going around the apple.  He doesn't play with the other kids on the playground but tends to like one girl who is more into playing with the boys.  On the flip side at home he plays extremely well with his older brothers and even his own friends. He is very good at communicating but often wants things his way. We did have him in another childcare before this and they didn't have any of these issues with him.  Or at least they didn't say anything was going on like this. He had his share of biting for a month and some time outs there but I wasn't told any social issues. Any feedback is greatly appreciated.
Thanks-

[Jason C Bourret, Ph.D., BCBA-D]

If you have any concerns, I always recommend having the child assessed. There’s no reason not to. It’s impossible to make a diagnosis without seeing the child but many of the things you describe aren’t uncommon in typically developing children and the facts that your son plays well with his brothers and friends at home and is an effective communicator are all very positive signs. The thing to do, whether he ends up receiving an autism-spectrum disorder diagnosis or not, is to make sure he’s receiving help in the areas that he’s struggling. Additional tutoring and help with the eating issues could make a huge difference for him.