NEED ADVICE PLEASE !!

I'm a first time mommy, 37 weeks tomorrow, I'm having SEVERE back pain. it hurts no matter what I do. I've had it since 2 am and it's currently 2 pm now. I've been laying on the heating paid, walking around, laying down, stretches. nothing is helping. but I went to the doctor on Thursday and my cervix is still closed. so is this pre labor or just the joys of pregnancy ?? please comment, anything helps !! thank you. 😊