Right on the brink
Typically, O2 sats while asleep in a healthy individual should be >90.
If yours are typically hitting 90 or below then, I'd say you are right in the crack between barely normal and barely abnormal. I'd think for a 19 year old nonsmoker you could do a bit better than that so it all depends on what else is going on. That number by itself doesn't diagnose OSA but "yes" you could have it.