My name is Brian. I was diagnosed with sleep apnea and haven't received a CPAP yet. I bought a pulse oximeter and have been monitoring oxygen levels in blood for several nights. I am seeing a pattern that oxygen levels drop just when I am between wake and sleep. The rest of the night is fairly normal 89+. When I had my sleep study, I didn't sleep well and remember waking up frequently and think that this may have contributed to the diagnosis (as would have been in wake/sleep transition many times). Any thoughts on whether this really represents central sleep apnea or if this is normal?