CONSTANT LOWER BACK PAIN. 36 WEEKS PREGNANT!

Need advice. 36 Weeks and my back is in so much pain I moan every time I’m laying down and switch to sleep on my other side. It is a constant ache (this came out of nowhere two days ago) and my tailbone is hurting and feels like it has so much pressure! Just a few days ago I was told that I hadn’t dilated at all but baby is in a -1 station. Could this be why? I’ve been having tons of Braxton Hicks and a few period like cramps here and there. Haven’t lost mucus plug. Just need relief because this pain is unbearable!