Uy, totally normal yan sa 31 weeks! Parang may heaviness or pressure sa pelvic area diba, parang gusto mo lang mag-CR kahit wala talaga? A few of my preggy friends at ako mismo dati, ramdam namin yan especially pag tumatagal kaming nakatayo or naglalakad kasi the baby's getting heavier na and pressing down sa organs mo. Try sitting down more often, wear supportive shoes, at iyong pelvic floor, pero honestly, since nararamdaman mo na yan quite a bit na, mas safe kung i-mention mo to sa OB mo next visit para sigurado lang na lahat ay okay pa rin!