Hi Everyone. Thank you for sharing your experiences. They sound like mine, except mine are not severe.
I have been having the same exact experiences as described by the original poster during the last month -same side, same duration.
My blood tests and my blood pressure were normal this year and in general I feel great. It doesn't sound like it's heart related according to another medical website that I found.
My pains are more like a sharp "stickery" sensation under my left breast in my rib area. The pains repeated enough that I didn't know if it was a sign of a heart attack. It happened when I went for a pleasant walk this evening...I wasn't out of breath or anything and now it has stopped again. So maybe it's an "electrical" thing as someone mentioned.
Peace and Health,
P.S. I just had another 2 pains again as I finished typing. If anyone figures this out please post. Thanks.