Question about Menopause

My doctor is no help because he says, "It'll happen when it happens, dont worry". Ugh, I want to punch him in the throat.

My question is.. from what you all know, When do women usually become menopausal? I mean.. does it matter how early you started menstruating? Is there a test I can get done that can give me a better idea of how long I have? What are,legit, symptoms of becoming pre menopausal?

I started menstruating when I was 2 months past my 10th birthday, my mother and her sisters all started 16-18 yrs old so they are no help to me.

I am just curious because AF is changing and I have had it for 27 yrs on October 11th.

Thank You in advance.