My LO turns 2 in a week and a bit and I am not sure if I should be concerned about his speech.

He says probably close to 50 words not all clearly.
He follows instructions quite well.
He rambles all the time like in his own language.
He doesn't join words together yet well ones that make sense.
He responds to his name
He did go backwards a little bit when his sister was born.

Not sure what other points I need to cover...but anyone have/had a similar 2 year old?
Is he just a late talker or should I be more concerned?