Yep, it’s a known thing. As Shazzie says, probably to do with the slight, hormone-driven rise in body temperature.
I went on the mini-pill as soon as I was diagnosed, although I’m not using it for contraception (not seeing any action, so don’t need to).
The periods you get on the pill are not proper periods, so although I still get a slight worsening of symptoms when I take my one week’s gap, it’s not at all as bad.
I’ve also got the OK from the doc to run two packs back-to-back, so I only get one bleed every two months - fantastic - and saves a fortune in sanitary products! Especially as my natural periods were down to every three weeks (getting near the end, now - some people’s get further apart, some more frequent). Eight weeks compared to three is paradise, as far as I’m concerned!
Apparently, it wouldn’t actually be harmful to health to go longer without a gap, but nature tends to get a bit insistent, and you get breakthrough bleeding, which is annoying and inconvenient, so the best compromise is a two-month cycle.
I have to have regular blood-pressure checks (regular actually being annual, so it’s not too bad) in view of my age, but it’s made a big difference to quality of life.