40 is a little young to start Menopause, but not unheard of, it can happen. I started @ 49, for 1 year, I would bleed for 7 weeks, then it stop, started, did that for a year. I have not had a period for 2 yrs now. I started gaining weight a little weight in my mid section, I also got very depressed. I'm not a depressed type, always happy, not moody. I had to go on Prempro, it took 2 weeks, I was better.