Please tell me this is not pre-menopause

I am 37 year old with my tubes tied. My normal period comes pretty much on time give or take a day or two at most. Periods are usually very heavy, whole pack of pads in four or five days, very painful and a lot of clots. This month I've started spotting a week before my period is due, absolutely no clots or cramps. I've been spotting off and on for about five days. Have had to use about two or three pads and that's barely even enough to change it. Highly doubtful it's imolantion bleeding as my tubes have been tied for almost 9 years. Should I be concerned about this drastic change?