((hugs)) When I was pregnant with my fourth, it was included with the prenatal testing for ME. If I wasn't a carrier, then my kids could NOT have CF. And, we were at a birth center. Could you call the BC and see if they ran that test on you? It might ease your mind.
When my third had his CF scare, he DID taste salty. But, he didn't have CF. So, if you do lick your son, know that if he's salty, he still may be negative. We had him tested at the allergist/pulmonologist. With poor Grayson's ongoing symptoms, I'm really surprised that they haven't sent him to one. I'm so sorry.