Help me fast?!!!!!!!!!!!!!!!!!?!?

I'M ONLY 15. A few days ago I went to a children's hospital because I had lower stomach and back pain, they did an ultra sound to see if it was my kidney's but they said it was fine. Then they thought maybe I had appendicitis, but they couldn't see, it was inconclusive because I was constipated, but I go everyday. Now my stomach hurts in the upper part closest to my ribs, I'm having right and left shoulder pain underneath and when I breath in my back hurts really bad, I'm also having pain in my right armpit and and it's bothering me, so I was wondering if you have any ideas of what it could be.