Pain in right shoulder/ below right collar bone

[agowder2]

Last Wednesday I had a burning sensation below my right collar bone - almost like heart burn. I felt like there was air in my stomach, which caused me to belch a lot.  It intensified to the back right shoulder (in between my neck and where a bra strap would land). Over an hour or so it intensified to my neck and the top of my right shoulder.When I breathe in, I feel a sharp pain in my shoulder - almost like a running stich. The pain was unbearable. Over the counter pain medicine didn't help. It lasted about 6 hours. I went to the doctor the next morning (the symptoms subsided by then), the Dr. ruled out pulling a muscle, it doesn't hurt to move my nexk/arm and my neck is not sore - i didn't lift any thing out of the norm. The next day I got an ultrasound of my gallbladder, it came back clear. Over the weekend, I had 3 more episodes (not quite as intense, no belching). I called te doctor yesterday (Monday) and the doctor sent me in for a CT scan of my chest, which came out clear and later today they're doing a Venus scan of my legs for clots. I'm a 28yo female, so a clot seems unlikely at my age. I'm fine when the symptoms aren't happening...but when it does start, it goes from uncomfortable to super painful in about 10 minutes. It intensifies when I lean back or lay down. Any idea what this could be?