I'd use a monophasic, as there is less chance you'll spot on that since the hormone levels remain constant throughout the pack. You could use Marvelon, Demulen, Nordette, Ovral...pretty much any monophasic should work. If there is a Provincial or regional health clinic near you you could try calling them and going in to see them. They usually deal with a lot of young people and get many wanting to skip periods, so they may have some more suggestions for you. I know that in most Provinces, the clinics are for each region, and usally part of that region's department of health.

Good luck. :)