A "late talker" is defined as fewer than 50 words by 2.

My son is a late talker. He grows up in a trilingual environment, which may be a contributing factor. When he turned 2, his combined vocabulary was only about 15 words. I took him to a speech development evaluation, and the specialists concluded that he doesn't need any special intervention. Now 2 months after the evaluation, his language skill has improved dramatically. He has now a combined vocabulary of around 100, and started to form 3 word sentences, such as "Baby play ball.".

If you are worried, I think you should take your son to an evaluation. If there is no problem, you will get your peace of mind. If there is a problem, then the earlier you intervene, the better it is for him.