Choking turning into not breathing

I have already made an appointment with our pediatrician but want to know if anyone has had any similar experience and what was advised. My LO is 6 weeks old and has had a couple episodes where out of no where during the day she will stop breathing because she seems to be choking and turns extremely red and arches her back. Today was the longest amount of time. Almost 3 minutes before I could get her to breathe after doing her back pumps and called 911 midway because I was freaking out. I know it’s common for them to choke on saliva/mucus/milk but the not coming up for air is scaring us to the point we can’t sleep at night because we are afraid it might happen then. LO is strictly breastfed. And hasn’t had any issues with nursing. Any advice on this??