Contractions (cross posted)

Ok mamas. Bear with me I'm a first time mom. Where are contractions felt? I've been feeling dull tightening starting from my sides and ending in the center once every 20-30 minutes that last 15-20 seconds in the red area. Of course I started timing them. But is that where they're they're supposed to be felt??? I'm almost 40 weeks my hips ache too when I feel it