Could Pain Around The Lower Right Abdomen Be Due To Colon Cancer?

I have been experiencing pain in my lower, right abdominal region. I had a full hysterectomy 17 years ago. It is getting more irritating and sometimes pain genrates around my back and down my right leg. I went tot eh doctor this past Weds. the 8thand he put me on antibiotics as I also had congestion in my chest from a cold, he said the antibiotic should kick everything out and if after a few days I still have the same abdominal symptons than I will need to go back to get my abdomen untrasounded. I have had 2 cousins die of colon cancer and an uncel die of bladder cancer. what could this be?