Is it possible to go through menopause at 31?

Possible, not likely: If you are having hot flashes or NT sweats at age 31, i suspect they are from a side effect of a medication, such as antidepressant, or that you have Progesterone deficiency and/or adrenal fatigue/insufficiency. Other symptoms of menopause, such as mood swings and trouble sleeping, these can be related to above as well. Night sweats can also be a sign of something serious, so get evaluated.