What Causes Vaginal Discharge And Foul Odor?

I left a tampon in me for 10 days at least. I had no idea it was in me and after the foul odor and discharge thought to check. What should i do know? do i need to see a doctor? i don't have any symptoms of TSS, other than i was feeling tired and achy for a while. But I feel fine today but my vaginal area is itchy. I'm 46 and healthy