I use Utovlan. I get it from superdrug online pharmacy, it's pricey - about ?20 for a week/?30 for 10 days? but a Godsend if you can't afford to have a period. It delays my period, ie, taking it 3 days before I'm due and then every day until I want it to start.
However, as an experiment (

) I did take a day (or two) dose of it
during a period and it stopped, but it started again when I stopped taking the pills (so I sort of split my period in two) The cramps the next day were killer but I survived.