(Ok. i know as well as anyone that vampires dont sleep but I had a whole idea so please let me do this)

Subjective precognition is your ability to predict future events using mechanisms other than the five senses, You've recently been getting this at night which you usually dont have

Strange.

Carlisle therefore asked Jasper to stay extra alert when your asleep

10:30 PM

You've just woken up again which Jasper had sensed while he was just a few meters away from your room

When you tried to go back to sleep you heard a knock on your door, it was Jasper