Weigh thing.. Do i have a problem?

Im 18 years old, 5'4 (yeah im a shorty :p) and 118 lbs and i think that im fat. Everybody tells me that i'm skinny but i just dont know. I used to be super skinny, the kind of almost see through skinny, but i have gained a little weight and at first i felt good but now i don't. When i meet with people who knew me before they tell me 'oh, you gained weight' and i dont take it the good way. Do i have a problem cause everybody sees me skinny but i see myself fat?