Oo normal lang yan, mama! At 17 weeks kasi lumalaki na talaga ang baby at umuunat ang ligaments mo, kaya parang may bulges at tigas ka minsan lalo na pag tumagilid or nagbabago ng position. A few of us mums noticed yan din around that time, tapos parang nawawala pag nag-relax na or nag-stretch, it's your body adjusting talaga. Pero kung ang sakit sa balakang at tagiliran mo ay nagiging persistent or super intense, better check with your OB just to be sure everything's okay, para peace of mind mo na rin! Breathe, mama, pregnancy is one wild ride pero karamihan ng ganitong symptoms ay normal lang sa second trimester.