O.,
If you had reason to worry about autism, you would have written a much different post. Most of us with atutistc kids knew that something was wrong before anyone suggested that speech was a problem. You have reason to get him evaluated for his expressive language, yes, but remember too, he has two langagues that he is learning, and that is a lot of processing to do. Since it is Russian, it is a whole different alphebet, and different sounds too. It would be good for you to reach out to your local elementary school and ask to speak to the ESL teacher (English as a second lagnague) and ask if you can get some references for speech therapists who also can evaluate his Russian langague skills...you will not get the whole picture of his langague use if you only evaluate his English. It may take some digging, but find someone who can evaluate both, and who can tell you how to weigh this very special circumstance with clairity, so that you are not needlessly worried, or seek any therapy that may not be needed. I don't know how the two languages will figure in, and it may just be that he needs some assistance with his English, such that he uses it more and does not develop an expressive issue. Right now, there is no reason for you to panic about anything. You have a very young child, and you are seeking help for what is probably a minor issue.
If you have bigger worries, they will find you. But, that is not the whole story. It is not a happy thing to have a child with a disablity for sure, but you will not have a different child than the one that you love and adore right now. You will still feel over the top about him, and that will not change even if there is a ton of letters that describe his needs. Love, you will still love him, and do everything you can so that he will have a happy and wonderful life. Our kids are more like other kids than they are not like them. If it happens to you, yours will too. Right now, it has not happened, so don't fret.
M.