Oo, normal yan, mama! Around 35 weeks, ang tigas tigas ng tiyan mo (Braxton Hicks contractions) ay talagang mas frequent na, lalo na kung active ka pa rin or minsan kahit pahinga lang. A few of us mums noticed na parang nag-harden ang belly namin every few minutes, tapos biglang soft ulit, super weird feeling talaga pero part lang ng pregnancy preparation. Since you're close na sa due date, definitely mention it sa OB mo sa next check-up para peace of mind, especially kung may pain or unusual cramping, pero in general yan talaga ang normal na signs na preparing na ang uterus mo!