Unbeknown to us at the time, a friend in our group had been trying for a baby for years, then started on IVF. I cringe at the amount of times the rest of us said 'are you going to have kids then or what' and she just sort of smiled and laughed and said 'yeah maybe'.
She told us the whole story when she was pregnant with her first dd and in a way I can understand because when she went through her next IVF, we were all on eggshells around her, which she understood but hated.
She had wanted to keep things private between her and her dh, which I respect, but I never ask anyone anymore just in case.
On a lighter note, one of my other friends was asked 'how often are you having sex though?' by a practical stranger!!!!!