Stomach tightening

im at my 34 weeks now. my stomach has been super tight especially after dinner, and will constantly be tight till i fall asleep. when my baby moves, it feels even tighter and painful because of the movement. What's the cause of this? Im not sure if its Braxton Hicks because i read that it last few seconds. But for mine, its longer. There isn't any other symptoms. Is it because i eat too much? Or? FTM here. Thank you in advance :)