Hi last year i had an vaginal discharge it was dark brown i went by a doctor and he recommended i use metronidazole vaginal gel, i used it for five nights and the infection was gone. i still have the metronidazole gel because all the gel in the tube didn't finish.for a few days now i been getting a dark brown discharge spotting and it smells bad. Can i use the metronidazole gel again since i have it? with the same tubes? or will i have to go back by a doctor first?............it will expire next year