I have experienced that in both side of the scale........
I think our bodies go through lots of different sensations that sometimes coincide with lower or higher blood sugars, obviously there are the more well known symptoms of higher and lower levels, but its the subtle ones that can sometimes confuse us.....
Definitely go through it though.........I often think I am higher than I am because I think I can smell it believe it or not, but then my BG is OK.....