What Causes Severe Pain In The Right Side Of The Stomach?

hi, im an 18 year old female, and i have noticed it all started in i think November or so.. the pain is not constant and doen not stay. on my right side i get without warning a stinging, pinching pain that comes unexpectingly. i am able to go on and live my life but i just want to know what it is??? can u help? also near the right side of my belly button it can be sensitive when u touch it. but not pain pain.. idk i just want to know what it is??