It took us about a year. My wife had endometriosis, so she had an op to clear that out. The gyno said if you are not pregnant in 6 months you should try IVF (which neither of us wanted to do). Anyway, almost 12 months later we went to see another specialist. We should've saved his enormous fee, because we were already pregnant
You know you are in trouble when your wife starts charting her cycle
Good luck!