Ok please tell me how much your 20 week baby weight? My son is 11.2 lb and becouse of poor weight gain we may be sent to sweat test for cystic fibrosis and im just freaking right now. Hes irt levels came positive but genetic test came negative for cf but he had lungs x ray and there is mucous build up and our pediatric said we may need sweat test. Im so stress that its hard to breath . Any moms with cf children's can they tell they stories please 😣