Get a support belly band to help take pressure off your back, use ice or heat too. Swimming is a good exercise and can help you stretch out your muscles. Good luck!
Prenatal yoga! It helps and there you can learn specific stretches and postures to help with specific issues.there is a partner pose that works wonders where you squat while partner holds your hands (hard to explain) and cat/cow pose is great for taking the weight off
Rest and some tylenol is the best I can offer for this weekend. I highly recommend prenatal yoga classes. I went to an 8 week series and they teach you great stretches for you back and hips to help the soreness and strain. It's worth looking into for natural relief.
Hope you feel better
When i went to physio they said that upper back pain is due to posture. Try to keep your back straight. And for lower back they recommendedto get on the floor on your back. Put a big thick book under your lower back where your tail bone is. Bend your knees and rock your legs togethrr from side to side gently 20 times. It hurts but it does make it better.
Hope it get better for you x