What Causes Pain In The Upper Abdomen?

Hello. I'm a 33 year old female. For a while now, I've had some pain in my right mid-upper abdomen. I had an abdominal and pelvic ultrasound in February which were normal. I also had a CT scan with contrast, a small bowel follow-thru, an endoscopy and a gall bladder function test. All were normal except for some gastritis and some bile in my stomach. The CT scan also showed a small liver cyst which the GI doc told me not to worry about. After the CT scan (in April 2011) I started to feel much better with the pain coming and going and sometimes being relieved after a bowel movement. Now the pain comes and goes but I also experience bloating, gas and constipation. The constipation I've had my entire life as far as I can remember. The pain comes and goes and sometimes by stomach gets very hard. Sometimes I also experience lower back pain on the right side. I'm so fearful of ovarian cancer. What are the chances of this? I have 4 children ages ranging from 3 to 9. Any advice would be greatly appreciated.