Sayang, cyst tu memang boleh jadi, tapi kena jumpa doctor atau OB-GYN untuk check , jangan worry dulu, okay? A few of my mum friends ada history cyst during pregnancy, and most turned out fine with proper monitoring, tapi yang important is you get it checked properly so they know exactly what it is and whether it's related to your back pain. Jangan self-diagnose lah, let the expert guide you, some things memang perlu professional eyes. Aight, go book that appointment, and take care!