Hey mama, white discharge is super normal sa pregnancy, especially towards the end, pero since you're already 39 weeks and wondering if it's labor, best to mention it sa OB mo next visit or call lang para peace of mind, kasi they can check properly kung may changes na sa cervix or kung may mucus plug na. A few of my mum friends were paranoid din about every little thing near their due date, pero honestly the safest route is always just a quick check with your doctor, especially if it smells funny or may other symptoms like cramping or spotting. You're so close na, mama, sending you labor vibes soon!