Horrible/constant back pain-start of labor??

I'm 37+3 today...I woke up with a constant pain in my middle and lower back that is radiating to my belly. The pain is mostly towards the top of my stomach and it feels like a lot of pressure upwards. It's very hard to breath. This has been going on since this morning so roughly 12 hours. I do feel pressure down below also but not really like crampy feeling. I was thinking it might be contractions but it doesn't really ease up. My water has not broken. I'm trying to hold off going to the hospital as long as I can. Anyone's labor started out like this??? This is my first pregnancy. I have been on the verge of gestational hypertension. They were planning on inducing this coming Friday. I just don't know what to think..??