Just Curious What Might Be Causing Intense, Spontaneous Pulsating, Throbbing

Just curious what might be causing intense, spontaneous pulsating, throbbing pain just under my left rib cage. I am not one to get alarmed needlessly so am curious if it is just normal. I am 76 yr old female in good health, active and younger than my years. I do take BP meds and cholesterol med, nothing else. I took a hard fall yesterday on my right side, but am only kinda sore today....am I being paranoid?