Hospital

So last Sunday I went into the hospital for back pain and was contracting & my cervix was shortening I'm only 26 weeks they sent me home with medicine to help & medicine for a uti because I had the start of one. On Wednesday at my app. They checked my cervix and said it had shortened even more told me to keep taking Medicine and I'm on bedrest well today my back is hurting again idk if I should go in? They keep sending me home but my pain isn't going away is this just normal?