Is the world playing tricks on me?

I am 17 years old and got my period when I was 13. I have gotten it every month, unless I purposely skipped it using birth control, and it has always been 7 days long. I got my period this past Tuesday, the 24th, so I expected to have it until Monday. But it ended today??? This has literally never happened to me before. I’m pretty happy about it, because my period is quite treacherous due to my endometriosis, but I’m just really confused lol. Anyone else have an experience like this?