A drastic change in lifestyle/diet seems to modify people's periods, this we know. So I'm thinking... maybe I can go on a temporary extreme diet? Get into some intense exercising? SOMEthing?
It will change your period length if you do this. The drastic change will drastically change your body. Your body will become used to that new drastic change and when you go back to your normal patterns and habits your body will go back as well to accommodate whatever environment it is being supplied. Whatever your physiology decides is what it is going to follow, no amount of praying or swearing (I attempt to swear it off with anger-does not work, go figure lol) will change it.
Most people here know I am 100% devoted to science and 100% endorse actual medical manipulation to garner a true effect instead of trial and error methods...but if you do not want a doctor or drugs then absolutely no amount of information should change your mind. But I can say I have heard of pseudomethods of just thinking "change my period" over and over...of course there is literally no reason to believe that works but hey its just words and no drugs lol. But really, you are talking changing your physiology and to do that you need to use a method to change that, so diet and exercise and a lot of it. However if your diet is already okay and you exercise a lot then your kinda stuck with what you have period wise.