I noticed the other day an odor coming from my vag. At first I thought maybe a yest infection, but there is no itching or burning. What else could it be?

There is some kind of infection in there - that's why it smells. Go to your doctor and see what is causing this problem. Try as we might we just can't diagnose stuff like this over the internet. Smellonet has not been invented yet. Could be a number of things. Possibly a STD is brewing there. It does not have to itch or burn to be a STD either. I'd make an appointment at the soonest possible time and see what this is.