does my 6 year old son have tourette syndrome

i first noticed my son whos now 6 twitching at the age of about 2 it first started with him lifting his sholder always the left one then he would rub his foot up againsed his other leg . then he would rub his face always n the same place they seem to stop for a wile then he started to look up  using his eyes never moving his head and also opening his mouth really wide as of to streach his jaw and now its excessive blinking and repeating the same sentance a few times when he is telling you some thing . and he also has problems with his throat like he has some thing stuck in it but thats not all the time only occasional . also he has a neck twitch  they seem to get worse when hes excited  i nevery gave this much thought but his teacher aproched me recently and im really quite worried now because i have read other post and he seems to have most of the symptoms can any one tell me what i should do thanks