Oo normal yan sa pregnancy, lalo na around this stage kasi lumalaki na ang baby at umuusog ang lahat ng organs mo! A few of my mum friends nag-complain din ng same thing, especially pag gabi or pag tumatagal sila standing. Try mo lang mag-rest, warm compress, or change positions frequently, pero kung super intense na ang pain or may bleeding, better check with your OB agad para ma-rule out anything serious, okay?