For the last 1.5 hours I've been getting pains in my back and tightenings in my bump. It comes in waves reaches a peak then receeds. I've times them and there anything between 5-10 mins apart and last 45-60 sec. Could thus be labour or is it just back ache. I've not lost my mucous plug or had a show that I'm aware of? Any advice would be greatly recieved?