So many respondants are correct in saying get the sweat test as soon as you can. I had only one vas deferens when my urologist went in to delete two vas deferens after my wife and I had two perfectly healthy (NO CF) children. He found one enlarged Vas Deferens and no sign of another. I have a milder mutation gene on one side (relatively good news)and the Delta F 508 on the other (not so good). I am currently 52 with two adult children with no CF health problems and only received a double lung transplant this year which is I avoid rejection and infections should allow me to live out a relatively normal life span.
My point is this, even if he has CF, there is a wide spectum of disability with CF, some that just impact your life without taking it over, ( also possible he has NO CF) and it is possible that he may have children that are perfectly healthy themselves. I would encourage you to get the salt test done and remember they are very close to a cure. I wish for you and your son hope, luck and a long healthy life. Kaiser Willy