Idk why but I just wanted to share this lol! For about 8 years, honestly it could be longer, my period ALWAYS comes on a rainy day, no matter where I'm at. I'll go out of town and think I've tricked it but low and behold, a rainy day will come along with my period, it's so funny. I can look at the forecast and see rain and can guess that it will come on that day.