The female reproductive system is highly complex, and for everything to work just right, several hormones, glands, and organs must do their jobs in the right order, at the right times. Once you understand how the reproductive system works, it's easier to understand how things can go wrong. It's quite a miracle that things go right at all, given how complicated the entire system is!
Also, being familiar with how the reproductive system works can help you understand why certain fertility treatments are done at specific times.
Long Before Menstruation Begins
We often think of the reproductive system as something that works in monthly cycles, just like our menstrual cycle. While this is mostly true, it's much more complicated than that.
The egg you may ovulate this month has been getting ready inside a follicle for the past 290 days, almost 9 months. In fact, that egg has been around as an immature egg since you were just a fetus inside your mother's uterus.
When you were just a wee one, at about 12 weeks gestation, your ovaries contained 6 to 7 million immature eggs –- the most you would ever have in your life. By the time you were born, there were only 2 million immature eggs left, and by the time you had your first menstrual cycle, your ovaries held just 500,000.
What happens to all those millions of potential eggs? Where do they go?