Ftm question

I'm 37 weeks 2 days and am a FTM. That said I'm under the impression that I Havent had any contractions yet. I have had cramping but nothing to severe and doesn't last long. I go to the Dr tomorrow and I'm guessing she will check my cervix but I just wanna know how everyone knows they are having contractions. It might seem like a stupid question I guess, but I Havent experienced anything.