For some reason, every night I sleep perfectly fine for the first 5-6 hours of sleep before apnea starts to kick in. So if I fall asleep at midnight with the goal of sleeping until 9:00 AM, I sleep peacefully until around 5:30 AM, after which I am jerked awake feeling short of breath and sweating. I fall back asleep, only for it to happen again and again every 30-45 minutes or so. This happens almost every night. Textbook sleep apnea symptoms.
I actually had a sleep study done at a hospital, but the study concluded very early in the morning (I think around 6:00 AM) before I exhibited any symptoms of apnea so they found nothing abnormal and sent me home.