Thankyou everyone - varied views but mumsnet is good for lots of different views which is what I was asking for.
Am going to ask the health visitor (GP who is normally a good GP didn't want to refer for his language or lack of it more precisely).
Not sure if they will refer me to a paed.Can you say I want referral or go privately?
I don't want to be neurotic (I am already fussy remember!) and do feel I am overanalysing things somewhat but it is hard for me to differentiate between normal toddler and possible ASD behaviour.
The lining up is really quite recent and may be a phase.It is however quite frequent at the moment - balls,toys.
I think his language is improving each day.He did for instance see some cheese on the shelf today and said cheese pointing and the same with his cup.
He wasn't doing the lining up at the picnic to avoid the children there - he just seems to enjoy it.Once it is done to his satisfaction he will then go off and play with something else but he will not be happy if you move things but he is also like this if his sister takes his favourite ball or does something else not to his liking. He has lots of mini tantrums throughout the day generally.
He does interact well with his older sister and they play together -usually chasing and ball games.I have seen him smiling and trying to interact with children/adults he doesn't know.
However I know ASD is a spectrum and language disorders can be difficult to pick up so I appreciate your advice.
Cyberseraphim it is interesting what you said about the books pointing in a similar way - do you think I should mention this to the health visitor?
Kewcumber, I agree it can be difficult when comparing your children particularly as dd was such an easy baby/toddler (not so much now though) who always slept,never had tantrums (really!) and reached all milestones early - PFB!- and ds is the opposite although very very lovable.