I'm 31 weeks pregnant and have braxton hicks , while walking today I had very painful contractions that even when sitting didn't seem to help them feel less painful , when I got home I've tried relaxing and they aren't as painful anymore and not very consistent should I go to the hospital or is it just very painful braxton hicks ? Also I've had very bad pain in my back the whole time

Well I would suggest that you HYDRATE - and IF you have contractions EVERY 5 to 10 minutes consistently and/or you are losing fluid - in other words if your amniotic fluid bag broke, or the baby is not moving around as much, or you are bleeding, THEN this is when you need to go to Labor and Delivery.
But, if you Just feel that you need to be evaluated, then I would suggest that too.
I hope this helps, thank you