True labor or false labor?

Having a hard time figuring out if the labor process is starting or if it is just false labor.I am 37 weeks and my doctor has said that it is okay to start the labor process this week. This is my second pregnancy but my first going full term. I have tried calling my doctor but the office has yet to answer me and I don't see my doctor until late tomorrow afternoon. I constantly feel like I have to poop but I really don't. I don't know if they are Braxton Hick's or contractions but they hard like hell and last for a good minute and happen about twice an hour and my whole stomach gets hard which when I was having Braxton Hick's early on, it was only a certain spot in my stomach that would get hard. I have been exhausted (yes I know that this is something that is common in the end of pregnancy) and I have no appetite at all. Baby moving has slowed down. I have been having period like cramps in my legs and my lower back has been hurting a little bit. I  haven't noticed a difference in my discharge and last time that I was at the doctor's I wasn't dilated.