Has anybody experienced prodromal labor?

I think that may be what I’m experiencing but I’m not sure. It’s been happening since last night around 10pm and it’s still happening. It started with a really bad back ache. I don’t have back problems really not even during pregnancy. And when it happened I was just sitting on the couch nothing strenuous. My back ache was accompanied with some menstrual type cramps. Today back pain is off and on not timeable either. Still having menstrual type cramps and some contractions but not close together. Also having lots of lightning crotch which isn’t helping. I’m just tired and miserable. My body just aches so bad. Does it sound like prodromal labor? How long before prodromal labor does real labor start?