But the strong odor, I don't know, sometimes it may smell a little gross (because your period is old nutrients and blood and that doesn't always smell so nice)

But is it like a strong dead fish kind of smell?

How long has this been going on?
Are you sexually active?
Have you been tested?

If you are sexually active, you should see your OB/GYN, it may be an infection. And by the "bad smell" I forgot what it's called, but there is a infection that does smell very bad and can be fixed with a set of pills taken over a week (I believe).
http://scarleteen.com/body/discharged.html
That little article may be of use to you too.