The only way the 'pill' stops a woman's period is if she continues to take it during the week she's supposed to stop. They take it for 3 weeks then have a week without during which time they are supposed to have their period. Never 'set in stone' when that happens or for how long though. Some packets only have 21 pills in, others have an extra 7 'sugar' pills so it keeps them in the habit of taking them over the 28 day period.
I never said I know SP's who use tampons, I said there's some who shove a sponge up and continue to work during their periods. Google is your friend if you don't know what that is.
You are describing the combined pill which is taken 3 weeks on and 1 week off. And I agree it’s not set in stone when exactly the lady will come on but you can certainly plan around it, there’s not going to be any surprises.
But you also have the progesterone only pill which you take continuously without break as well as the mirena coil, implants and injections which all stop periods altogether.
I’m not going to google sponges, I’m worried I won’t be able to unsee what I might see. It was an assumption that they are the same as tampons so fair play, I’m wrong again on that one. But surely they work along the same principles as tampons as in they soak up blood. And I wasn’t aware that SPs use things like this and carry on working. So even if you don’t personally know any who do, if you are aware that it does happen then my initial assumption that they all use hormones was wrong.