I'm 39+1 and it always happens to me specially when I walk, but it disappears as soon as I lie down on bed and take some rest.
I mentioned this to a nurse at my Dr and they said it was normal. But idk, it hurts to much sometimes to be normal
I'm 37 + 6 today also but I'm not having any problems. Haven't all pregnancy.
I would time the cramping/tightening and see if they become closer and more painful. If they go away after walking or even resting it's probably just Braxton Hicks.
I'm 37+2 it's just your body preparing for the real thing i get it often once you unwind abd relax it normally stops.