Sayang, please see your doctor or go to the hospital straightaway, at 31 weeks, any sudden belly pain kena check dengan proper, jangan tunggu. Ini bukan something to guess-guess at home, okay? Even if sakit datang kejap-kejap je, better safe than sorry. Call your clinic or go to A&E sekarang, they'll check if it's Braxton Hicks or something else. Don't delay, ya. Sending you strength!