Hi mama! Light yellow discharge is usually normal, especially near the end of pregnancy kasi ang body mo is really active na, but since you're already 37+ weeks, better to mention it to your OB just to be safe, pwede syang check if it's just the normal increase or something else, kaya walang worry. A few of us moms nag-experience din ng ganyan towards the end, pero it's always good to get the go-ahead from your doctor para sa peace of mind mo, lalo na first time mom ka pa. You're almost there na!