i am confused by many opinions

My son is 3years3months old. He had normal birth etc. He doesnt seem to have motorskill problems even swims well. My nursery suggested screening and psychologist after first visit said he might have thin line of autism. He is still back in speech and psychologist said his speech isnt delayed but seems to have a problem. He is very good in receptive but doesnt speek, has a short vocabulary but improving day by day lately saying the alphabet and recognizing letters and adding new vocabulary oftenly but no sentences and doesnt answer question except wit yes or no. He lines up cars but not obsessively and loves puzzles, blocks building (imitates too), and gets involved. He doesnt do alot of eye contact but shows affection to people even strangers even gives kisses. He answers his name but sometimes seems to ignore and does ignore cause he wants to but knows all is happening around him. Going through traits of autism yes there things that occur but not obsessively, the biggest problem is speech mostly. it is confusing cause when i go through traits some get you confused for example toe waling but few seconds in a week aint normal? except for speech and eye contact duration i see little signs that are really red flag but at sametime i get confused going through obsessively about everything he does> he is healthy, full of energy and a busy body, independant and i ve seen him at summer school he engages in playin with other children holding hands in games etc yet when we told teacher that we are doin tests she said that sometimes he plays a bit on his own but nothing that seemed to wry me cause he engages in classroom activities as much as the average children do.I can go on with contrasting evidence that really confuse.