sounds muscular. have you strained your muscle doing any vigorous activity and not rested it? i have chronic chest pain from a cracked sternum and it flares up all year
Time to see the doctor. Could be gallstones or kidney stones.
Honestly that sounds like the same sort of pains I get from my gallbladder attacks. I have gallstones and if I eat any thing high in cholesterol -pork, eggs, dairy; or high in fat, anything fried, red meats, oils; or anything alcoholic my gallbladder freaks out and sends pains that are unbearable. You really need to check with a dr about this because if you do have gallstones then sometimes they can get stuck and cause really bad problems like jaundice and infection.