Daycare says our son has fewer words than others his age. Wait till two, or get him checked now?

I do the daycare pickup, and yesterday his teacher stopped me at the door and said, very kindly, that he has fewer words than most children in his group. He says amma, nanna, 'ta' for anything he wants, and one word that seems to mean both water and the neighbour's dog. He understands a lot. He follows instructions, and brings his chappals when we say we're going out. Our paediatrician said at the last visit that boys are often later and to wait till two. My partner would rather get a speech assessment done now and stop wondering. I can see both sides, which isn't helping either of us decide. For those who were in this spot with a toddler, what did you do? Did you feel afterwards that you'd waited too long, or rushed it?