Yup. The pill is actually made up of 3 different tablets which are taken in a particular order. The first lot do nothing they are only there to keep the cycle of pill taking regular. The next lot stops ovulation and need to be taken at a certain time of the month and the 3rd lot induce the period. If a girl skips the last lost then no period.
The other thing that is fairly common is sponges so they can work through their period.