labor?

Ok ladies. I'm a ftm and I know very well that labor is different for everyone and every pregnancy, but I was wondering if it's normal to not have any Braxton hicks contractions through pregnancy and if labor/contractions can really just kind of start out of the blue. I'm currently 38wks 3 days and I haven't felt anything that I really think is Braxton hicks throughout my entire pregnancy. There have been a couple times where I started feeling real crampy like I was getting ready to start my period, but it's never been waves of cramps, just that constant crampiness you feel during your period. Usually when I have felt these cramps is when I haven't drank enough water or I worked myself too hard physically. I'm getting really impatient as my doctor has already estimated my son to be on the large side and I would just really like to avoid tearing/being cut and a c section.  Has anyone else gone into labor out of the blue after not feeling any Braxton hicks? Could those have been Braxton hicks?