It could be many things, from your gallbladder to your appendix, you could be constipated amongst other things. Best thing to do is see a doctor soon.
The right side of my lower abdomen is hurting and it also stings. I feel a bit weak and I want to vomit! What could it be?
Could be gall bladder/ appendix, you're best to go to the hospital / doctors though!
It could be appendicitis, if you tab (gently) on it and it hurts like a devil, it probably is. Anyway I would go see a doctor because if you don't treat it could actually be very dangerous.