Perimenopause

Maybe someone in here can relate and tell me im not alone..So recently I went to my yearly doctor exam and told her about how off my periods have been. My whole life they have been pretty normal up until the last 6 months or so. Instead of them coming every 28 days they come every 17-19 days. When I told my doctor this and that I think its perimenopause she brushed the whole thing off and blamed it on my weight. I told her my weight before has never changed my periods and I have actually lost weight since the last time I have been in and she still insisted thats what it is. Is anyone else 35+ and gone through something like this where your periods just start coming earlier than 28 days?