Son may have ASD.... not sure what to expect?

Hi all

I am new to this so please bear with me. I have always known that my son is a little different... but in a good way. He could be described as slightly shy or quietly confident and I have always been so proud that he knows his own mind and doesn't follow the crowd as such. He is six years old. He went to a day nursery from nine months old and no issues were raised there. He then started pre school and they started to pick up on his lack of social skills and that he played alongside other children rather than with them. They started to do work with him on talking in small groups and his confidence improved. 

In his reception year at school the teacher said he was on her radar but no serious issues. Just that socially he was a little behind but was improving. She was a very experienced reception teacher who I have great respect for. Last year - year one, he had a very unsettled school year with part time teachers and several supply teachers. Overall he found it unsettling. Towards the end of the year the Senco teacher asked to meet with me. She raised various issues about lack of concentration in the afternoons, social skills, difficulty in changing clothes and lack of eye contact. I asked what she thought this was and she raised Aspergers. I already had an inkling myself but struggle to see where he may have a disability or where he just has a quirky personality. We have now been referred and are waiting on further tests.

My son has a spiky profile, he is very loving and empathetic, makes lovely eye contact once he is comfortable with the person, clever, funny and thoughtful. He does however have fixed interests, talks about trains/cars in great detail and often, lacks interest in playing with others unless they are playing his game, quite clumsy in the physical sense and doesn't like loud noises. He will often take himself off when playing in a group of friends and play on his own however we can then go to the park and he makes a new friend very confidently. 

I am not sure what I am after from the forum, just examples and stories that other parents have about similar potentially high functioning children. I am deeply worried about how this will affect him as he grows up. I only want him to be happy and have positive relationships with others. So far he is a very happy boy and is not troubled by his differences. 

Thanks