Sayang, first of all tahniah on your 3rd pregnancy! Sakit tulang rusuk dan pinggang ni memang lebih common bila dah masuk trimester akhir sebab rahim makin membesar dan baby pun dah mula bergerak aktif, so it does put more pressure on your ribs and lower back. Ramai yang find it helpful to sleep on your left side and tuck a small pillow or rolled towel right at the curve of your lower back, it helps support the spine so you feel less strain through the night. A heating pad on the sore spots pun boleh bagi relief yang agak ketara, and do try some gentle pregnancy-safe stretches regularly, even something as simple as using an exercise ball to ease the tension around the rib area and hips. My sister actually had this same issue in her third pregnancy and her physiotherapist reminded her that loose, comfortable clothing matters more than we think, anything too fitted around the bump area can worsen the discomfort. That said, since your pain is quite persistent and this pregnancy feels different from before, it is really worth mentioning it specifically to your doctor or an O&G specialist, just to rule out anything like sciatica or other concerns that need proper attention. Take care of yourself, dear!