Yesterday and today i've had really sharp abdominal pains coming and going. they can go from sharp pains to a subtle pain, what is this?

Could be many things: ranging from as simple as gas pains, to as worrisome as appendicitis. It also depends on where the pain is (lower, upper, etc). If you have fever, bloody diarrhea, severe vomiting, vaginal discharge or heavy bleeding, burning with urination, or severe pain, you should get seen right away. Otherwise, try simethicone for gas, or ranitidine for acid reflux for a few days.