Heating pad, essential oil massage.
I use stretching to help loosen my pain multiple times throughout the day. Or I have a heating pad which helps a bit. But it has been really hot where I live so I don't use it as often now. I try my best to stay active. I feel like if I have to sit too long it makes my pain worse. I have also read there are some topical creams which do not contain Methyl Salicylate which can help ease pain. Good luck!
I find a hot water bottle on my back works really good ive got the worst back pain ever was in a bad car crash in December car was a complete wreck we all should be dead it was so bad and I ended up with a lot of other damage anyway I conceived in January and was on morphine prior to that for my back pain now I obviously can't take anything so I use hot water bottle and take things easy also Bowen therapy is brilliant words can't describe how good I found it but its too far away for me to travel for sessions ATM, I wouldn't try any new age stuff like yoga or acupuncture x
Chiropractic care helped me. But make sure its a specialist with prenatal care. Do cat/cow yoga exercise (youtube it) also prenatal yoga has been really nice when I have a rough day. Good luck and good job for searching med free options