Wear a ring pulse oximeter while sleeping. my average spo2 is between 95-97%. the lowest it gets down to during the night is usually 89-91% but dropped to 86% one night. average pulse rate is 46-49 and i usually run 48-50 awake. is this normal?

You may have sleep apnea. You can video yourself, especially your upper part, during sleep and if you observe your head or breathing change which correlates with the low SpO2 episode, obstructive sleep apnea (OSA) is likely. Sleep apnea test is recommended if you have risk factors for OSA such as overweight or obesity, short neck and you snore often during sleep or feeling sleepy in day time.