Salam sis! Back pain at 30 weeks is SO common, aku pun pernah, memang macam nak mati rasa dia Try wearing a maternity support belt (betul-betul tulong, seriously), and jangan berdiri lama-lama or sit in one position je; a few of us mum friends rotate between sitting and lying down every 30 mins and it helps. Warm compress or ask hubby for a gentle massage on the lower back area pun membantu, and make sure posture still okay even though sakit. Tapi since this is affecting your daily life, best check with your doctor or midwife to rule out anything serious, they might suggest physio or give you safe exercises for your weeks.