Sayang, hardness or tightness around the upper belly area at 17 weeks is quite common, uterus dah membesar and ligaments pun stretch, plus sometimes kita punya organ lain (liver area) pun terasa tight sebab pregnant, tapi since you're worried, better to mention it to your doctor at the next check-up just to be safe, especially if ada pain or contractions. A few of us had the same thing and it turned out normal, but tak salah confirm dengan doctor je untuk peace of mind you!