Mommy, please check with your OB as soon as you can, abdominal pain kahit gabi-gabi ay hindi dapat i-ignore, lalo na sa ganitong stage ng pregnancy. Hindi ito normal na dapat lang tanggapin. A few of my mum friends din nag-experience ng similar discomfort, pero lahat nag-consult right away dahil maraming reasons bakit pwede mangyari, from stretching to something na kailangan ng checkup. Better safe than sorry, especially at 31 weeks ka na. Anong dala mo na sa OB mo? If it's severe or you feel anything unusual, go to the hospital na agad, okay? Sending you strength, mama.