Mothers,fathers do you know?

Hi ,ok so me and my wife having been trying for our fourth child with the last eight months we have had an unlucky time as we aren't conceiving ,i have noticed with the last week that in the middle of the night her chest and forehead is like almost a blanket of sweat i noticed it when i touched her its not like her to sweat like that at night as she is usually complaining it is cold and she also seems to talk in her sleep would there be any signs of her being pregnant or is there something else wrong