35 weeks and 4 days is still within the normal pregnancy range, hindi pa siya considered early delivery, pero yung sakit sa balakang at pempem mo ay normal na sa ganitong stage kasi lumalaki na talaga ang baby at bumababa na siya, a few of us mums felt the same thing around this time! Pero since you're experiencing pain, mas better na i-check mo with your OB just to be sure everything's okay at para ma-ease your mind, lalo na kung medyo intense na ang sakit or may other symptoms pa.