Does this sound like early labor?

I have had a very thinned out cervix with baby's head able to be felt during internal exam for about a week now. I was diagnosed with short cervix (down to 1 cm at 31 weeks) and have a lot of scarring from previous procedures so my dr could never really tell me how effaced I was (said he couldn't really tell what was cervix vs. Vaginal tissue but that I'm still closed). I'm now 37+2 and today I'm having consistent lower back pain coupled with painful menstrual like cramping lower in pelvis. They seem to be timeable, about 30 minutes apart lasting about 30 seconds for last 1.5 hours or so. Does this sound like early labor? I don't remember going through this with my son I just woke up with full on contractions, maybe I just slept through it?