Help . I'm waking at the same time every night

witching hour.. Or.. You're finding some importance in the numbers, maybe superstition, and causing yourself, subcon, to wake up at that time.

The body clock is an amaizing thing. It's gotten me out of a jam often. If you tell yourself to wake up at 4am, you will. You may fall back asleep, but you'll wake up at 4am. It's a weird thing.

I think you're expecting it. Probably watched the exorcism of emily rose recently

You'd be surprised how powerful the mind is over the body.
The other day I knew I needed to get up at 10am to go to school, it was 6 something and I misread the clock.
I thought it said 8:30 so I fell asleep repeating "must sleep for an hour and a half" sure thing I work up 90ish min later and couldn't go back to sleep.

Maybe you're seeing something with the number 3 before you go to bed.