if it were me I would go and talk to your GP be as open an honest as you can and explain that you are worried about his little quirks and would like to get some early intervention if there is something going on. In my experience it is better to get early intervention for a child who is quirky then wait until they are 8-9 and already really struggling with school, friends and society in general. (this is from both a teacher and a parent/aunty's perspective)
Thanks Saram, i've written a list of things to talk to the pead. about at Ethan's appointment on Monday. Its strange, now that i'm looking into the signs/traits of ASD its like i'm seeing Ethan through new eyes.. i'm seeing things now that i just put down as quirkiness but i now realise there might be more to it. Of course he's still Ethie and always will be no matter what the pead says

Perhaps with the plugs it might involve you having a toy or something and getting in his way with it, or bumping into the plugs with a big 'oh no ... they fell over' ... sorta thing. What else can you use the leaves or nut things for ? you could make one a car and interact with his plugs that way.
Thanks barbie- up, great advice I usually play along with his pretend plug games, but i'll try to be more exagerated
His plug obsession is really driving me nuts the last few days. He is CONSTANTLY talking about plugs and repeating something about plugs over and over until i repeat it
back to him. I've tried distracting him and that works sometimes but usually he'll just keep repeating over and over And he constantly wants to play with the sink, which i don't mind him doing as it makes him happy but the problem is he keeps wanting me to fill the sink up and then pull the plug out so he can watch the water go down the drain... its very frustrating as i can't get things done because he's constantly asking for 'more wawer' and having tanties because he can't reach the drain hole to put the plugs in. Ahhhhhh! I have to even sneak into the bathroom to wash my hands because if he sees me anywhere near the sink he comes racing in and wants to play with the sink. What i'm struggling with is whether or not to indulge his obsession? Do i just let him play with the sink and plugs? Or do i try and limit it? I tried not letting him play with them for 2 days and it was like his obsession doubled. Lots of tantrums and constant whinging Any suggestions?