Aik, perut mengeras macam tu normal je dalam trimester 3, sis, uterus stretch habis and hormones pun buat gas problem. A few of us mommies had the same thing, especially after makan sikit je tapi rasa bloated gila, pasal baby dah besar kan so less space. Try makan slowly, avoid gas-trigger foods like beans or carbonated drinks, and walk around a bit lepas makan, helps with the discomfort. But kalau suddenly sakit or tightening becomes painful/regular, better check with your doctor, okay?