Lets start with what led to them doing a sweat test......if he had some classic symptoms of CF & they test was borderline that I would push for genetic testing to find CF gene mutations.
If they tested just for ha ha's (dont why they would, but you never know) then I wouldnt push it.
Since the cases are usually that you CANT get doctors to test for CF you should be grateful they tested, but it sounds a bit "inconclusive" to determine for sure. The doctors that did it or the ones you are going to in July....are they an accredited CF center? The sweat test needs to be done by one to assure accurate results.
If you could give a bit more background that led to testing maybe we would have more ideas for you.....