I dont know pdd.nos/ autism/apergers

my son was given a pdd.nos @ risk for autism back in 2009. As time goes by he has taken us on a rollercoaster ride he has taken 2 steps foward then 2 back he just recently left his diapers again age (4) for a full month know:) he had before then regressed all the way back.I have always had problem with my walls he always seems to find something to draw with when we all got together and hide ever single writing tool he decided to get creative and use bar soaps toothpaste etc "its a masterpiece" he says which it is(big big drawing somteime a whole wall ). he has had trouble keeping his clothes on he always likes to be clean he does not have friend he plays around them but not with them his always had trouble in big crowds even when he was a baby he slept thru his 1st birthday party and other big event people use to say he was just a real good baby and know I just think he was overwhelemed I always knew something was up. We took a 24hr road trip to visit family and he did great till we got there he cried for hr s @ a time day and night  he still does not like to visit others and he still does not like his routine changed he knows that when he gets home we get in the car to go pick up his older brother and the days that dad picks him up he gets upset becuase i dont open the car for him he has no idea of the danger around him his been bumped by a car after he ran right in front of it and the days the bus is late he runs from the bus stop in the direction he know it come from he used to cry at nights nothing would confort him not the tv his blanket nothing he start to ask for a pb&j sandwich a cup of milk and yogart but not eat them just line them up on the tv stand he has stop know but he still sleeps with us. He progressed after that his speech is a lot better when he first started to talk he would say normal baby words like mom dad then he stopped not one word just pointing know he is able to communicate the sound is not perfect for his age but the word is there he great at numbers 1 to 20 color all including prewinkle?  abc=his favorite shapes including the cresent and diamond he prefferes to say beautiful insted of cute and he loves to say masterpice o and perfect:)his very proper useing his thank you's please sorry etc so I always hold high hopes for him. Its been a month know he started to do some odd things he can be watching tv and then he just takes off and tags the lofts walls and the hallways the goes back and claps but only useing his fingure tips he does this alot in a day he does complain of loud noises and cover his ears sometime even crys he has always liked us to write the abc and draw a picture for each put he get real upset when we cant or we dont do it exactly the way he wants it its inpossible to get him to do it  he has a real good memorie he can remeber words to a song and all the movie i mean all the movie he tells us which way to go daylight or not he knows his way around our close streets. and some street that we use once in awhile he can use the kids web pages on the internet with no help after it on the right location o when he started to talk again we and everyone around him notice his aIways very loud and cant wait his turn especially if he know the answer he'll just let it out his special needs teacher tells me if another kid is haveing trouble he will reach over and do it. I can go on and on but if i can have an opinion about this I want to get my son(4) an aspergers eveluation is this a good idea?