Everyone is so different so it's impossible to say for sure. But for me I would not describe labor pains as dull and achy, they were very intense and crampy. I'm pretty sure you would feel the contraction threw your whole uterus, some woman feel it more in their back but I've never heard it to only be on one side. Perhaps get in the bath and try to relax, see if that gets rid of the pain, if it gets more constant or painful maybe call your doctor or L&D
I suppose so, I actually was wondering the same thing. I've been having that all day. My mucus plug came out and as of last week I was 2cm dilated.