Ay alam ko yan, mama! Back pain sa pregnancy is super common, lalo na pag second baby after a long gap kasi parang nag-reset ang katawan mo, pero honestly with the CS scar mo baka mas nag-stress ang spine mo ngayon. A few of us tried pregnancy pillows, warm compresses, at proper posture (kasi talaga, mahirap maging careful pag busy ka na with kids) pero since you're already 27 weeks, best to mention it sa OB mo on your next visit para ma-check kung wala nang complications at ma-advise ka properly. Hoping you feel better soon, girl!