I'm not saying DS is perfect but don't see him as Autistic
Why not? Serious question.
I think what you mean is he doesn't appear to have what you think is autism, which is probably not a true picture.
If he is autistic, he was born with it and will always have it, whether there's a diagnosis or not. If by some miracle he was diagnosed by a multidisciplinary team tomorrow, he would still be the same boy he is today, you would not see him as any different today than you did yesterday. He would not BE any different today than he was yesterday.
I'd suggest you do a lot of reading and watch a lot of videos about autism. The SN boards on MN are a mine of information and help, particularly SNChat and SNChildren in my opinion.
You are likely to encounter a lot of myths and prejudices along the way.
Everybody seems to have an opinion on autism, yet they often know very little about it. Unfortunately, most are in denial and insist your child could not possibly be autistic. Ignore them.
Please be acutely aware that no-one can diagnose your child with autism or say definitively that he does not have it apart from a (team of) qualified clinician(s) who are trained and qualified to do so.
The team often consist of Paed, Ed Psych, SLT and OT, there are others but that's usually the main ones who all assess children and reach a conclusion after much testing and comparing results.
Autism is a medical diagnosis, see above. Many people disparagingly refer to autism as a label, that is so demeaning and disablist. Autism is a medical diagnosis, the diagnosis is not given lightly, sometimes the process can take years. A medical diagnosis is not something you stick on a jar of jam or a suitcase, so why refer to autism in such terms?
No empathy, cannot make eye contact and many more boys than girls have autism are common myths and are repeated by people who really should know better.
'We are all on the spectrum somewhere' is the biggest load of codswallop, see here for a very good explanation. A few traits does not mean someone is autistic.
theaspergian.com/2019/05/04/its-a-spectrum-doesnt-mean-what-you-think/
Here's a more child-friendly view
the-art-of-autism.com/understanding-the-spectrum-a-comic-strip-explanation/
This thread perfectly outlined the benefits of diagnosis in childhood, in case you've not seen it.
www.mumsnet.com/Talk/am_i_being_unreasonable/3629648-to-avoid-getting-my-son-diagnosed?pg=1
One of the worst myths is 'High functioning' means mild autism, no-one would know they have it' 'High Functioning' means someone has an IQ over 70. Nothing else.
There is no such thing as mild autism either, the diagnostic criteria say "The characteristics of autism vary from one person to another, but in order for a diagnosis to be made, a person will usually be assessed as having had persistent difficulties with social communication and social interaction and restricted and repetitive patterns of behaviours, activities or interests since early childhood, to the extent that these "limit and impair everyday functioning". Source NAS www.autism.org.uk/about/diagnosis/children.aspx
A lot of people who will be replying to your thread will have young children with autism. As the parent of an autistic adult, I'd like to say that my experience is that the behaviour you see as a child changes as the child grows up. Some things that would provoke instant meltdowns for hours in childhood are able to be tolerated in adulthood. Don't think the presentation of autism you are seeing will always be the same. Some things diminish, some heighten and others stay in the background. The anxiety will always be there, but the individual can learn to cope with some of it resulting in reacting in much less less extreme ways to whatever triggers the anxiety.
It's a vast subject, made more difficult to understand because everyone who as autistic can present in a totally different way to someone else who is autistic. It's best to understand your own child and then advocate for them to obtain the interventions they need to be put into place at school. Your current school sounds as though they are very pro-active. They are not telling you there is something "wrong" they are telling you so that you can pursue a diagnosis and IF your child is given one, they can put in extra support.
In theory, schools should be able to support every child based on their needs alone, in practice, a diagnosis can help to secure extra funding.
It all depends on what area you live in as to what services are available.
Some kids with ASD have a lot of sensory processing needs, here's a very informative leaflet www.falkirk.gov.uk/services/social-care/disabilities/docs/young-people/Making%20Sense%20of%20Sensory%20Behaviour.pdf?v=201507131117