Sayang, kalau belly hardening at 37 weeks tu memang normal, Braxton Hicks contractions lah tu! But since you're asking and concerned, please check with your doctor or midwife soon just to be safe and confirm everything's progressing well. A few of us mums had the same thing at that stage, and most were fine, but sebab dah close to due date, better get your doc to check arah-arah baby and when baby might come. Don't worry, you're almost there!