I think that some people may be more disappointed to not hear of sucess stories of people they have been conversing with rather than it having a negative effect. Sharing a bfp after going through the trials and tribulations with others that are ttc could potentially be inspiring rather than depressing.
Another idea would be to make a another section within the category of tww and ttc that is about success stories and advice of what they did that worked. (especially for those that conceive and have been trying for an extended period of time)
It is kind of like a good book or show, you have to know the ending.