Two year old behind on language?

My daughter will be two next month and I am concerned she is behind on her language. She understands plenty, but when she talks she doesn't make any sense. At first I found it cute and somewhat entertaining, but I'm noticing other kids her age make some kind of sense when they talk. She doesnt. This is jus tan example of how she "talks": "no no no, gwy! (crazy random babbling)" Its very random and she does it for no reason. Its not like she comes up to me trying to tell me something, its just random outbursts like these. Other kids her age though, they make a lot more sense when they speak and its at the appropriate times. I'm worried. A few months back I took her to a speech therapist who said she was a couple months behind but nothing to worry about. After a month her speech improved greatly and the doctor said there was no need for her to be in any speech therapy. I'm not so sure I agree. Am I just being paranoid and over analyzing? I dont mean to be this way, but I worry because after all she is my child and I want her to be ok. Any advice, experiences?