I have a foul smell after using tampons. no itch or discharge. goes away two weeks after period. but still bothersome.

Vaginosis?: I suggest seeing your gynecologist or family doctor and getting testing for bacterial vaginosis as well as other infections. You might have an underlying BV which is causing the foul smell (especially if it is fishy). Also reduce intake of sugar and starch and eat more green veggies to make your body more alkaline which should help some.

Mild infection: You may have a mild vaginal infection, or more accurately an overgrowth of some of the less desirable bacteria, known as bacterial vaginosis. It is easily checked and treated. Also, make sure you have not inadvertently forgotten a tampon.