I have just had a period after 6 month am 51 years old why?

Perimenopause: 12 months of no periods equals menopause. So we don't know it's the last period until 12 months go by and there is no bleeding. If bleeding comes at 6 months, you start counting the 12 months over again. 51 is the average age of menopause in the U.S., but that means half the women are done at 51 and the other half are still going. Be sure to talk to your doctor about irregular bleeding.

Perimenopause: Menopause by definition is no cycle x 1 year. As women age the hormone levels decrease but it not an on one day then all the suppen off for good. It is a gradual decline. It is not uncommon as you get closer to menopausal to go extended months without a cyccle.