I know I don't have stds. So what is it?

Lately I've had an excessive amount of discharge and my Vagina smells. No matter what I do or how many times I wash. Right after I'm done it smells. I made an appointment with my obgyn. I know I don't have any stds because I was just recently tested and they all came back negative. I just want to know if any of you ladies know what it could possibly be.