What Causes Vaginal Discharge?

I am a 65 year old woman who have never had any female problems. The last 10 days I have a lot of vaginal discharge. There is no burning, itching or smell. I saw my Ob-Gyn yesterday. She did a pelvic exam and found nothing. I had a vaginal ultra-sound which showed nothing. I'm waiting for results from a blood test and urine speciman. Two questions:What do you thing the problem might be. If the tests come back negativie do I pursue i



Thanks,

Darlene Johnson