I am having sharp pain in my left shoulder blade along with slight nausea and numbness down my left arm. It is pretty constant although does get a little sharper if I breath in deeply and the pain inceases 10-fold if I cough. I had a similar problem at the same time last month that lasted a week and a half. At that time I went to the doctor who did blood work and a chest xray,but didn't find any issues so assumed it was a pinched nerve of some sort. It went away on it's own. Now a month to the day, I am having the same issue. I'm mid cycle and should be ovulating around now, not sure if that is somehow related but wanted to mention it because the timing seems more than a coincidence. I'm not on any medications and stopped taking birth control pills 3.5 months ago. Any ideas on what might be causing this?