My periods started to change in my early 40s, when I was 43 I went 4 months without one. Now they are erratic, so always have to be prepared. This is common in peri and can continue for as long as upto 10 years with hormonal fluctuations up until full menopause and no periods.
I started HRT last year due to physical symptoms, anxiety and brain fog.
Hope that reassures you. Xx