Ay, normal lang yan mommy, maraming sa amin nararamdaman yan around this time! Ang baby mo ay lumalaki na talaga at nag-shift na ang ligaments mo, kaya yung mild back pain at occasional tightening sa puson ay ganyan talaga, especially pag nag-move or nag-adjust ka, yung Braxton Hicks contractions na yan. But since you're already 35 weeks, best pa rin to mention it sa OB mo sa next check-up, kahit mild lang, para ma-confirm na lahat is on track at walang concerns, lalo na kung biglang maging frequent or strong.