I'm 17, got my first period at 11, and I've been regular as clockwork ever since. I have pretty lengthy cycles. In the last four months they've been 28, 30, 31, and 34 days long. This month my period isn't due until the 15th or the 17th.

But today I think I started, my underwear was soaked through and bright red, and I put in a tampon for a few hours. When I took it out it was half soaked and brown.

So why is it a week early? Is it actually my period, or is it something else? I'm thinking it's possible it's my period, because I've heard that stress can throw it off balance, and I've been really stressed lately.

(Possibly unrelated... I'm also suffering from what could possibly be a yeast infection.)