Ay alam ko yan! Ako rin nag-alala dito ng mabuti sa fifth pregnancy ko, kasi talaga naman parang iba ang feeling compared sa first few. Yung pagbibiring ng puwerta is usually normal lang, it's your uterus practicing contractions, especially more noticeable kasi marami na kang births, pero since you've never felt this before with your other kids, best talaga magpa-check ka sa OB mo just to be safe and get peace of mind, especially kasi advanced pregnancy na yan at mahalagang ma-rule out kung walang issues. A few of my mum friends din nag-experience ng different sensations sa later pregnancies kasi iba na ang uterus after multiple births, pero still better to confirm with your doctor para sure lang. Congrats sa fifth baby!