how to tell the diff ?

Macy
I'm 37 weeks 4 days 
Went to my doctor on Wednesday and he says I'm 1.5 cm dilated 
But my cervix is really really soft , forward facing and measuring about 39 weeks.
He asks me if I have contractions I tell him no
But after his examination he told me I'm deff having some just not noticing .
I just lost a piece of my plug So things are moving along.
My question is how do you tell your contractions from the baby moving ?
I just keep mistaking them for my child moving I think .