You don't have to have the 7 day break, but I guess women find it reassuring to know they aren't pregnant. But yes, you are right, the week break is not necessary. However, doctors reccommend that you should have 'a bleed' every 3 - 4 months. I hate always giving links in answers, but other people explain stuff better than me and by providing a link, it's a bit more helpful I think. Ok, here's your link!
http://www.fpwa-health.org.au/contraceptivepill.ht m