Horrible back pain!

Currently 9 weeks 5 days, for some reason, the last two days my upper back has been Killing me! I have a high pain tolerance (had my first son pain med free) and this pain has me in tears. Bending, laying down, getting up, everything hurts. When I stand up straight, breathing hurts and the pain radiates into my chest. I feel fine otherwise, but does anyone have any idea what's wrong or ideas to help? My rice heating pad helps temporarily if it's in just the right position but so far that's it.