Ay, kapit lang mama! You're so close na, literally a day away from your due date, so your body is definitely doing something kahit feel mo pang false labor lang. Ang sakit sa balakang at singit plus the low belly position ay signs na baby's definitely getting ready, kaya huwag mag-worry na nothing's happening. A few of my mum friends had the same experience and one of them delivered within 24 hours after feeling exactly what you're describing, so trust your instincts and your body talaga. Pero since you're already 39 weeks + 6 days and feeling so much pain, best na i-check mo agad with your OB or go to the hospital para ma-monitor properly, mas better peace of mind for you, at least alam mong lahat ay okay with baby. Fingers crossed for you, mama, you've got this!