Extended family and the kid ?

Every time I visit family/extended family I dread the questions of "do you want kids? Do you have kids? You've been married for awhile when should we expect kids? I always answer "we are trying" which sounds too tmi when you think about it, but what I really want to do is word vomit all over them about how personal of a question that is. How do we combat this while educating our loved ones that sometimes it just doesn't happen that easily?