congested premie

Casey
My baby was born 34 weeks gestation & spent 6 days in the NICU. She's 13 days old and she is soooo congested. She's all stuffed up, sneezing, and her breathing sounds rough at times. I took her to the dr, who swabbed for rsv & it was negative (praise God). I've been using a humidifier, saline spray, and a bulb aspiratior. It's day 3 of this & im honestly pretty worried. Anyone else go through this or have suggestions to help or what it could be?