Just shows how totally different everyone's experience is of perimenopause! For last 3.5 years since peri kicked in this has been me:
Going along as normal with period of 5 days every 4 weeks but nothing awful, just a bit heavy day 1-2
Then get an 8 week gap, feel vile with anxiety, big boobs.
Then get one horrendous period of heavy bleeding and clots that lasts 2-3 weeks
Then cycle settles back into normal periods of every 4 weeks again for about 9-12 months
Then the pattern starts again...this time period every 8 weeks and they went from 10 days in length to 3 weeks...
(GP and hospital check at this point with ultrasound, hysteroscopy and biopsies to check all OK - all well)
Back into normal periods again but this time 6 weeks apart but back just to 5 days of nothing too awful for about a year again...
Then 8 week gap again...and hey presto..
Just having a 4 week long one of heavy bleeding/clots again

My system seems to do these big drop downs/ups(?) of hormones I think which leads to this pattern as I can sense during those 8 week gaps hormones fannying about again.
How many more years this may go on I don't know...52 and a half and no HRT but had very low ferritin and for first time recently tipping into anaemia - there's a surprise!