Autism? Hearing problem?

**edit**
Thank you all who have commented. All of your help has given me the info needed to push for a referal. Just to note, I absolutely realise that autism presents itself in so many different ways, I hope I haven't offended anyone, just wanted to give readers as much information as possible.

Hi!
I'm super nervous about doing this, but I'm not sure what to do!

I'm a mum to the most beautiful 3 year old boy. I love everything about him!

At times I wonder if he may be autistic.
Doctors health care nurses ect tell me he is fine but for some reason its always on my mind.

To be honest I'm not bothered if he is or isn't, I believe people with autism are a gift to this world! But I wonder if I am doing him a disservice by not looking into it more?

He is SO verbally behind his peers, he doesn't speak in sentences. He has only just started calling me mum and dad, dad. He still babbles alot like an infant, but they are babbles with a purpose, almost like he has made up his own language in his head and he doesn't understand why others can't understand him.

Its a struggle to get him to play with things, his interests are usually anything that has a purpose, vacuum cleaner, kitchen stuff ect.
He is obsessed with our cars, he wants to know how everything works.

Emotional outbursts, he has these giant emotional outbursts. Previously it would involve kicking, hitting, biting and breaking stuff. Lately its gotten a lot less severe. He will hit and bite himself but he tries really hard not to do it to anyone else.

He is paranoid about people touching his head or ears, I can't cut his hair. He won't wear a hat. Every time he needs his ears checked it requires 3 people to hold him down. I have considered a hearing problem but Dr says his ears look OK but won't check his hearing until he is 4.

Now here's the conflicting stuff. He understands feelings, he understands when someone is upset. He connects with people ok, he seems to have a select few favourite people which I believe is typical of his age.

He sleeps and eats probably better than most children!
Lots of noise doesnt seem to bother him.

Hopefully this all makes sense and is enough info. I'm not sure if he's just a bit behind developmentally or if there's something more going on. I'm not even sure how to get a doctor to refer us to someone, or who that someone might be!

I really have no idea, i have no experience with this stuff and I just want to make sure we are doing everything we can to support him in his world 🌎