I'm a couple of days late on this, but...
my 3rd child
came home at 4 months old. He did not say his first word until 23 months. We had early intervention come out to our house from 19 to 21 months, but felt it was getting in the way of attachment (he was struggling at the time). By 24 months, he only had 3 or 4 words, but could identity all of his shapes. By 26 months, he knew a few more words, but could identify every letter, color and number. At 31 months, he only had about 50 words (none together and very unintelligible) but could ride a two wheeler without training wheels

. I truly believe he was very very busy working on other things.
He started special ed preschool for speech back in August (at 38 months). He speech has made huge strides (multiple sentences at a time), but he is still a little behind for his age. I really do believe that some kiddos just do things a little differently and at their own pace. That said, I was very worried about my son for a long time...thinking of all the scary things that could be "wrong".