Because you are so younge I would worry about it. Sometimes when you have a really heavy period the month before you might have some dark brownish discharge with your next cycle because you body was not able to get all the old blood out on the previous month. I dont think that you could get an infection from your shower head, I never did lol, but if you start to have iching, burning while peeing or a stronge offensive odor from your vaginal discharge, you might have a yeast infection. But that is nothing that a little monostat cant take care of, and just to let you know yeast infections are not sexually transmitted so you can ask your mom to go buy you the medicine.

Thanks for the advice! I have duely noted it