Signs of labour?


So since thanksgiving I haven't really been hungry at all... I've lost my appetite which is very unlike me lol my feet and hands have also swelled up out of no where. I've been getting minor cramping which I assume is Braxton hicks on and off for days (not painful). This morning I felt the cramping and as soon as I sat up on my bed I got a sharp pain from my stomach all the way down to my pelvis and even on my butt with a lot of pressure. Idk what this is as I'm only 36 weeks and a couple days. (so they say, I might be 37) My due date had been changed by a week earlier due to my LMP... but my doctor still goes by the old date for some reason. Can someone tell me what they're symptoms were before Labour? and did anyone give birth before 40 weeks without being induced for medical reasons ?