Yellow discharge?

I’ve had yellow discharge for some time now. It doesn’t smell bad at all. It looks white on my hand but yellow on toilet paper.

I have never had oral, vaginal, or anal sex, but I have had hand contact with someone who has had sex. I got tested for stds, and all my blood work was good but my urine test was invalid (testing for gonorrhea/chlamydia). My doctor said I don’t have to come back, he’s not worried as long as I don’t show symptoms. Is the yellow discharge a cause for concern even if it doesn’t smell?