Is stopping ovulation safe?

I remember in Biology cles, the teacher told us women had about 400 eggs in their ovaries which basically says how many periods you are going to have. But being on the pill, especially for years, means that women stop the eggs from being released. But don't they NEED to be released? Does that mean that you will have a later menopause and carry on ovulating and menstruating for much longer than you are supposed to?