everyone is different in the way it happens, i think. i was still having regular periods at your age, sometimes light and sometimes heavy, and my doctor said she thought i was quite old to still be having them!! the mood swings and pms were definitely the worst symptom, and that started a good few years before any interruption in the monthly cycle. if you google 'menopause' you'll find out all about it, along with the 35/36 symptoms which you have to look forward to, some of which you would never connect with menopause (itchy skin, stomache problems, tinnitus, sleeplessness), not to mention a hairy chin, thinning hair, acne........
best of luck.