I Have For Two Days Had Pain In Right Side

I have for two days had pain in right side from centre of spine and going across buttocks and hip. Also affects the nerve in right knee. I am on apo-lezetrol for breast cancer and my bone density has depleted whilst on this for `18 months. however this feels more into the muscle near the spine. I am wondering if it could be a kidney stone and or infection or urinary tract infection. It also aches occasionally on right side of bowel at bottom end. I have had some cephalexin 500 mg left in my bathroom chest and taken 3 since yesterday morning. Initial two helped not so much with one today. I am away from where I live and not able to see my doctor. What do you recommend