Well, at the start of TTC we didnt really tell anyone. After about six months of trying and regular BFN i was feeling really down so I told my sister. I'm kind of glad I did becuase she has been really supportive. My parents have been wondering for a while why we werent having any kids so i told my mum we have been trying but havent told her we have been TTC for nearly a year. At least now I dont get comments from them about "when are we going to have kids". I also have the problem where my sister and SIL's have all had kids and my youngest SIL is also now peg. I know that people are probably now thinking there is something wrong with me. I used to let it bother me, but i dont anymore. Its noones business what happens in our life. So from now on when people ask "when are you having kids", i just say soon.
I think telling someone who is close to you is a good idea, especially if you know they are going to be supportive.