You may be able to pass on the virus, even if you don't feel sick yet. The flu incubation period is the time from when you ...

The flu can also cause a general feeling of fatigue or malaise, Ray says, as well as gastrointestinal issues like diarrhea ...

the incubation periods typically about seven days average. And so and that's from the onset of symptoms because you can have the flu and not really exhibit many symptoms for the first couple of days.