I Am A 54 Year Old Female Living In Utah.

I am a 54 year old female living in Utah. Just recently I have been experiencing vaginal discharge. The discharge is a light to medium yellow and is fairly light in flow, but seems to be picking up. I don't notice it every day, but at least 4 days per week. This started approximately 5 to 6 weeks ago. The last few days I have had lower back pain, not like a pulled muscle or disc issue, but deep in the skin/tissue area. I no longer have a menstrual cycle (endometrial ablation 11 years ago), I am sexually active but that doesn't seem to change the discharge, foreign objects would not be a possibility. I shower and change my underclothes daily. That's not much information to go on, but I'm hoping you can help. Any ideas?