I'm on the 26th week and i also felt tightness around my tummy and sumtimes tummy felt hard like watermelon! hehe
i always got these feelings after bathing or when i walk up the stairs, or after a very long walk or if i eat full. how bout you??
Normally if i start to feel like this i took a break for a while or lying sideways.
I also wondering wether it is happening bcoz i "over work" myself by doing those activity?