Really scared 😳

My LO is 7 weeks old and I've noticed for about a week she's having some funny breathing problems. More at night. She's breathing fast and moving her hands in her face as if something is blocking her from breathing. She won't/can't feed because she can't breathe when that happens. She's still wetting diapers and eating normal when that doesn't happen. It only happens sometimes not the whole night or day. I took her to the er last night and they said her heart and lungs sound good but it really concerns me. Any suggestion on what this might be?