Aiyoo don't worry too much lah, at 31 weeks Braxton Hicks mmg very common and usually nothing to panic about, especially if you've been rushing around or tired, memang boleh trigger lebih frequent. But honestly, if the tightening is consistent, painful, or comes with spotting or fluid leakage, better go get checked out je, doctor won't scold you for being cautious and it'll give you peace of mind (a few of my mum friends went in "just to check" and doc was totally reassuring). Rest is good, tapi jangan takut hospital, that's what they're there for, and 31 weeks is important enough to not guess-guess about these things if you're genuinely worried.