You can actually start perimenopause at a fairly young age. I started having symptoms in my late 30's. Even I thought I was too young and was imagining things so I didn't mention it to my doctor until about a year ago (I'm 42 now). She agreed that I am indeed in perimenopause. I later talked to my mother about it. I had assumed that since she had a hysterectomy due to cervical cancer at age 38 that I couldn't use her as a reference point. It turns out she hit menopause at age 36!

I was talking to my younger sister a few weeks ago and she mentioned all the symptoms she is having. She is having a hard time convincing her doctor that she is entering perimenopause. He thinks she's crazy and that she's too young (she's about to turn 38). I told her to go back and tell him about me and about mom so maybe he will believe her.

So, while it's not common, it can happen. Like Bad JuJu said, doctors are human and they may not recognize it because it is outside of what is considered normal.