2 year old with RSV

It’s currently 1 am and I was woken up by my son coughing super bad (he’s 2 years old) it’s his 5th day with RSV so I gently woke him up gave him a sip of water and he went back to sleep but I have an oximeter so I just decided to check his oxygen really quickly and when I checked it was at 92, I was frantic and woke him up because I read anywhere below 95 is a cause for concern. It ended up going back up to 95 and he fell back asleep but as I’m watching him I notice he’s using his lower stomach to breath which I don’t know if it’s normal or not (I have a video of it) but his oximeter is back up to 97 I’m just very worried and don’t know if I should bring him back to the ER. (we’ve gone 3 times now over the past 5 days for similar reasons and were sent home each time)