I'm 31 weeks and my stomach been tighten and it's 2 min apart and my back is killing me.. Any suggestion what it means ?

go to l&d .. just in case you're early ya know. .good luck

I tried everything it's not helping.. I had a doctor appointment today and Doctor said my baby head is down and he said if I feel any contraction or tighten I should go to L&D

I'd say Braxton Hicks but if it is consistent and doesn't go away, I'd get checked. Usually drinking water and turning on your left side (the side that provides more oxygen to your uterus) helps.