Perimenopause begins about 6-8 years before you reach menopause. During this time the levels of hormones produced by your ovaries start to fluctuate leading to irregular menstrual patterns; such as, irregularity in the length of the period, the time between periods, and the level of flow. At this time you are ovulating on and off, so you could become pregnant. Other common perimenopause symptoms are: hot flashes, night sweats, mood swings, vaginal dryness, weight gain, fluctuations in sexual desire, fuzzy thinking, trouble sleeping, fatigue and depression.
You are officially in menopause when you haven't had a period for 12 consecutive months. At this point there are no more eggs left for your ovaries to release and pregnancy is impossible.
Post-menopause is the period of life after you have reached menopause.