Pregnancy and already having children

Cheryl • Mammy to son age 6 and blue bump arriving New Year`s Eve 2015!
Hi,sorry it's a little long , just wondered everyone's views please :) im 9wks & 5 days :) my dating scan is 23rd of this month (8sleeps :D) this is baby number 2 as I already have a 5 half year old son... 
Question is as im going to be going it alone again I want him as involved as possible being a big brother i.e scans ect, make him understand a bit more, more for my own piece of mind as he's being tested for emotional attachment issues/Asperger syndrome. Everyone thinks I'm
Bang out of order including him to my scans :( just want everyone's thoughts please?