I find if you say that you don't mind whether you have kids or not, the (noseyparker) questioner goes all 'suprised' and starts going on about leaving it too late etc.
I didn't meet my husband till I was 31, 35 now and no family (we are trying). My neighbour, who is 34 and has been with her partner 10 yrs, has asked me twice. She even told me that she knows women who have great careers etc, and 'left it too late', and now can't get pregnant at 36.
I already feel a bit bitter, that it took me so long to meet my husband, when other people got their partners so much younger.
She is expecting her second now, and I know she will ask questions again. I feel like saying that 'we can't all be greedy guts, with 2 kids. we can't all have everything.
I think if you tell people that is a very personal question & that you don't like talking about it, this might shut them up.
I wouldnt' mind so much if the people asking really cared about you. Some of the people asking don't care if you have problems trying to concieve, they just want to get news out of you. If you said to them that 'some people (meaning the questioner)dont really care about us, but just want to get news, so I'm not discussing it'. This will give them the hint that they are too newsy.