All it means is how far you have to go when labor starts. And even then it can't tell how long your labor will be. For example, you could be 4cm for weeks but still have a slow to average length labor. Or you could be 1cm and have a super fast labor.
I didn't ask for any checks with ds2 and it was great!!! It was so nice not to be obsessing about a meaningless stat ( because even though I knew the stat didn't mean anything logically I am sure I would be reading too much into things). Now that you have a baseline I highly recommend skipping further internals, at least for a few weeks. You'll minimize the chance of infection and maybe have less stress.
Btw, I had been 1-2cm, 70-80%, -1 from 38-41w5d with ds1. I had one check at 41w3d w/ ds2 and I was 1cm and 25%. I was in labor 3 hours later (membranes had been stripped). I have a feeling that if they had told me that 1cm, 25% stat sooner I would have been upset. Glad I didn't know!
Beth
Beth