Hmm...this is a good question.
As far as I know, if you AP, there are 2 places you may end to:
The astral plane, where most of astral projectors end to,
The physical plane or etheric plane which is earth.You end up here if you aren't on a very much high vibration.However, this doesn't mean that you must be in low mood level to reach this place.It is not the lower astral plane, where demons exist, after all.
If you astral project, and can get really low(but not lower than your body where the lower waves are)and close to your body's vibrations, you can visit our plane.