I don't know your age, but as a cool old lady...

I would suggest you try to live your life everyday, perod or not. Just keep yourself prepared all the time. Make yourself a little kit that you keep in your purse or backpack that contains everything you need for your period, no matter when you have it.
Put everything in a cute zippered bag, with room for aspirin, napkins, tampons, some wipies, some extra panties, whatever you need.
Rather than try to change your cycle, or have to avoid unexpected opportunities...I would simply accept that periods are a part of womanhood, and live every moment you get to.
I wish you well.