Oo, normal yan sa 25 weeks, lalo na kapag lumalaki na ang baby at shifting ang center of gravity mo! A few of us moms noticed the same thing around that time, the extra weight pulls sa balakang at likod talaga. That said, since masakit na palagi, mas better to check with your OB to make sure it's just pregnancy-related pain at walang iba pang concern, kasi mas peace of mind ka na agad.