Honestly I would call EI and get an evaluation. You can ask your pedi for the contact information and you do not need a referral for an eval.
I know the decision to get an evaluation can be difficult but in the long run he will either get the help he needs or your mind will be put at ease if they say he doesn't need services. It's free, they come to your house and "play" with him during the evaluation so there is nothing major to put him through. Some states have longer wait times than others so that may be the only frustrating part. We didn't have that problem however. DD1 had an eval just a week after I called and within a month after the eval we started services. We started with PT at 19 mo bc she wasn't walking and soon added speech as we realized she was behind there as well. Since then she has been diagnosed with childhood Apraxia of speech. A lot of what you are saying about your DS reminds me of DD1. We could count "words" but she didn't use them regularly and even then they weren't complete words, just approximations.
It won't hurt to get an eval so if you are the slightest bit concerned I would go ahead.
April, mommy to Haylea (8/18/09), Hannah (5/22/11) and baby Hogan due 12/12/12! *sent from my iPhone*