I have 'dreamt' a couple of being pregnant before i was told and often before the people knew themselves, i have a very strong sense of de ja vu a lot but similar to the girls it's not 1 thing it's a complete conversation, surrounding etc.
I too wish i knew more about it and how i could strengthen this ability but at this stage i let it go, i'm hoping that when the day comes i REALLY need to use it it will be there.