Speech therapy?

My son is 2.5 years old and doesn't speak yet. We'll he speaks, non stop at that, but in his own language. He will only say single words like mommy, daddy, bus, car, and ouma (grandmother), and then he'll repeat words we ask him to say and he can make sounds of certain animals that we taught him. He also sings along to songs, but in his language, but some words comes out right. Sometimes he'll say bess you (bless you) after he sneezes.

He doesn't make at least 3 word sentences at all. Should we get a speech therapist for him or should we give him some time?

Thanks in advance