Ay, balakang pain is so common sa pregnancy, lalo na around your weeks, kaya mo yan! Para sa peace of mind though, better check with your OB muna before using any topical creams or patches like Salonpas kasi buntis ka pa, at gusto nating sure na safe talaga para sa baby. A few of my mum friends said their doctors recommended safe alternatives like warm compress, prenatal massage, or stretching exercises na mas okay during pregnancy, so worth asking your doc about those options too!