Backache not going away?!

Woke up at 3:45 to use the bathroom and I noticed I had this dull but painful backache. I had one contraction at 4 and not sure how long it lasted because I was trying to go back to sleep but it finally eased off but the backache hasn’t. Since then, I’ve walked around a little, changed positions, took a warm shower and it’s still there. Taking Tylenol now and gonna try to lay back down but I’m so restless I doubt I’ll be able to. Is this a sign of labor or just another pregnancy ailment lol? I’m 36+2 and have a drs appointment at 930 but that seems like forever away. Thanks!