Severe back pain on one side

I went to L&D on doctors orders with severe one sided back pain, convinced I had a kidney infection. They said I did not have any infection and my pain was too low to be kidney related, apparently I pulled a muscle really bad that hurt bad enough it set off contractions which made the muscle pain worse. After three days in L&D with them giving steroids and drugs and fluids to stop contractions I have finally been sent home on bed rest with an MFM appointment Friday. The contractions have stopped but back pain hasn’t and I’m miserable sitting with a heating pad and waiting till baby gets here so I can take Advil. I’m 35+weeks and really wanting her to stay in longer but at the same time I’m really miserable. Kinda hoping the MFM moves my c section from 38 weeks to 37 weeks 🙏🏻