Throbbing pain on upper left side of ribs under boob,pain constant for mins and fades, had x-rays done everything normal. wht can it be?

Left sided pain: Pain that lasts for minutes and fades in the upper abdomen usually is related to the transit time of stool through the large intestine. Xrays cannot always detect constipation or excess gas which can cause these symtpoms. I would try taking Miralax (polyethylene glycol) or another otc mild laxative. If the pain is still there, consult a gastroenterologist.

Several thoughts: Might be cardiac, gastric, pulmonary or muscular. Is it affected by eating certain foods ? Does activity bring it on ? Any effect with certain movements of arms or chest ? Tender when you press on the area ? Does deep breathing affect it ? In a 20 yr old woman, likely muscular, but the others cannot be ruled out..