I have 2 spinal fractures and I get a lot of upper back pain! Obviously mine has an underlying cause however it's been over a year now (car accident) and I wore a brace for 3 months. I'm now 9 weeks pregnant and if I lift anything, bin bags etc for a certain period of time, my back begins aching and throbbing. The pain is horrible, combined with lower back pain! If I stand for too long, tidying etc, same thing! I lie down with a hot water bottle! Try that, if not go a&e xxx good luck!
Upper back pain is probably from you cleaning a lot. I wouldn't worry about it unless it was lower back pain or doesn't go away