if you don't sleep facing the ceiling (many people sleep on their side or even face-down) and if you turn around while sleeping (it's also pretty sure that you'll do this while asleep ;)) you're going to apply pressure on the piercing and it's "pushed a bit inside". Do you have a patch on your nose while sleeping ? There are these white fluffy patches that you could put on while sleeping, this will reduce a great amount of pressure. It's also wise not to drink caffeine or alcohol or watch tv/movies 2-3 hours before going to bed, because this will increase ones "activity" during the night and you'll be rolling around in your bed more often ;).
last but not least I recommend that you try to put a PVPI antiseptic on the wound before applying the patch, (brand names of OTCs are e.g."betadine") this will reduce the swelling and possible inflammations/infections, because if you touch it (and everybody does when getting a new piercing xD) and it actually "migrates" a bit deeper under the skin, you're likely to carry some nasty bacteria inside with it. And possibly you would have to remove the piercing for the healing process - so please don't touch it (even if you want to test whether it has "migrated" or not) and put a patch on it (and a PVPI antiseptic).
Hopefully everything will be alright then ;)