I had back labor, it was all in my lower back not in my upper back, but maybe its different for others. It could just be the stress of carrying baby on your body. I would try streches, a warm bath, heating pad, and some tylenol if your really desperate!
If they're bad and sharp, then go to the hospital or call your doctor. That's what happened to me with my daughter. I couldn't take the pain and ended up going to the hospital. Turned out I was dialated to three already. Good luck!
That's what I was reading that it could be contractions and it scared me.
Might be back contractions. If it continues to hurt, call your doctor.