Hay, at 39 weeks 3 days yan na talaga siguro, mama! Ang mucus plug usually yellowish or pinkish, sometimes may slight blood streaks, at parang jelly-like consistency, if that matches what you're seeing, mas malapit na talaga ang labor! A few of us mums said we lost ours days before mag-deliver, habang iba naman nagsimula na agad, kaya walang set timeline talaga. Since you're so close to your due date na, best to message or call your OB agad para ma-confirm and ma-monitor properly, lalo na if may iba pang signs like contractions or water breaking, alam mo na yan, better safe than sorry!