Are you having night sweats? Hot flashes? Any other symptoms of menopause?
45 years old is not too early; I started peri-menopause when I was about 43 (I'm almost 49 now) but this past year has been MAJORLY different in my cycle, symptoms, etc. I went for 8 months without a period AT ALL, but still suffering some of the symptoms (altho nowhere near as bad as they used to be) ...& then suddenly in April, bled for two weeks straight! Ugh.
And now, here it is "time" for my period again, but no period. However, I am having ALL the symptoms & having them BAD! - cramping, bloating (major bloating!) headachey, backache... mood swings out the wah-zoo!
It's a hellacious thing, being a woman.