Sweat test marginal, negative on the Ambry....Pulmonologist says no CF. After illness and illness, the nurse record what is happening; literally take videos. My daughter is given the vest. Still pneumonias and mucous plugs, but a little better overall. Still the wet cough all the time. Underweight and well under height(3%), chronic nose/sinusitis. My daughter was given hypertonic saline just before she turned 5. No more pneumonias....barely a cold. Pulmonologist then says she acts like her CFers. WE ADORE OUR PULMONOLOGIST! We started our Em on vitamins (a multivitamin), and she went from the 46th to 75th percentile for her size in less than 3 months. Could it be coincidence? Don't know, just like you in the dark. We (my wife and I) have now agreed, if it looks like a rose, smells like a rose, then it must be a rose. Prevent possible damage is our motto. I empathize for you. It has been 5 years for my family, and we are now finally seeing results with treatment, because everyone was and still is in the dark. However, the flashlights are working to get us through.