This is not true.. as said above, it's really the luck of the draw. I've had two sv's this past season. One where n started for 2 hours, d for an hour, then v soon after. The second one was on and off n and d, both pretty sporadic but it went on for a week.

My indicator, actually, is always the recurring watery d. That's how I know I might be sick. But it's different with every virus and every person!