I agree that 93 lbs is not enough, for a 19 yr old, and will make you underweight.
Male or female? What is your waist measurement?
Some drugstores have freely accessible body fat measuring gadgets (there are healthy amounts of body fat levels to aim for).
Weighing at 93 pounds at the height of 5'0 wil lead you to being underweight, I personally think that 96 is perfect because I'm 5'0 and I weigh 108 pounds :o but that's just my opinion...