Left lower abdominal pain?

For the past like 3 days or something i have been getting this pain in my left lower abdominal. sometimes its sharp and excruciating, sometimes i feel like im sick and im going to throw up, but on like a scale of 1-10, 10 being the worst, i would give it around a 5-7. its not unbearable pain, but it hurts like hell, but i can deal with it. but i dont know why this is happening? im only 13 btw. can someone help me please? and its not caused from working out or anything like that...