As you have no fever
and just a foulsmelling discharge you should not worry too much about it.You can take a broad spectrum antibiotic like Ciprofloxacin
500mg twice daily for 5 days along with B complex once daily.You should refrain from leaving tampons in this long as you might get Staphylococcal toxic shock syndrome
where a patient has fever ,septicemia
and goes into shock due to the toxins released by the bacteria.