Kristan, I got the same stitch like pain you describe just last weekend. I was so bad that even walking around and breathing was difficult. I ended up going to the doctors just to check if everything was ok. By the time I got in to see the doc, the pain was gone. He couldn't find any reason for it (initially thought I had a secondary infection in the lining of my lung from a cold/flu I had earlier in the week, but testing showed no infection).

He said it's probably just growing pain and to take it easy. I will be speaking to my ob about it at my next appointment tho, just to double check.

Hope your feeling better soon.