Your cervix can begin to open for several reasons (baby's head dropping, etc)...and you could quite honestly be having a contraction here or there and not realizing it. I have patients that we put on the monitor that don't realize they are having a contraction when they clearly are!!
How far along are you?

Yes it is, and it's a good thing as long as you are far enough a long! Just think of it as the dilation that you won't have to be in the pain of labor for