I am 15 , i have a lump on the bottom of my rib cage , it is soft , and when i push down on it, it is not painful or anything , it is just there. I also have sharp pains on my right side , it feels like the pain is coming from my heart, it happens randomly, when it happens it could shoot out a pain multiple times then a few seconds later it stops, this had been happening for a few months now and i am very worried about this.