Tightness around belly in second trimester

Hi mummies! I am nearing 20 weeks and have been feeling tightness around my belly >< It's more prominent from evening onwards too...the tightness feels like I stuffed myself with food even though I do not eat much for dinner... Anyone experienced the same thing? Is it just bloating or is it due to the growing fetus? #1stimemom #pleasehelp #advicepls #firstbaby #secondtrimester