Wa'alaikumassalam sis! Sakit perut memulas at 30 weeks kena perhatian, especially kalau dah 2-3 jam and painkiller je yang boleh calm it down. Please go to your clinic or hospital now to get it checked out, just to be safe. Braxton Hicks boleh sakit, but at your stage better get the doctor to confirm je, okaylah? Jangan tunggu lama-lama, better safe than sorry!