What can cause Chest rib pain for 2 years?

i have been living with chest pain for 2 years. I don't smoke at all, i am 21 years old ,athletic. For the last 2 years i am feeling a sharp stabling pain in upper right side and middle of sternum. the pain sometimes disappears and again comes back. I don't have cough . I went to doctor long time ago, but unfortunately i told him to check my liver as i suffered from jaundice when i was young. They did a liver test and abdominal x-ray which found nothing. So, i didn't care about the pain and living normally. but now it's making me worried. could it be something serious?