Do ovaries go through some cycles where there are no follicles?

You are born with all the eggs you will ever have in a lifetime. When you run out, then it is menopause. However, there are times a woman's body might skip ovulation because of hormonal factors. Stress on the body is usually the culprit. Female athletes have a higher incidence of this than other women because of the extreme physical demands. If you've missed a period but aren't pregnant, you might take a close look at your lifestyle. Have you started a new diet or exercise regimen? Are you getting enough sleep? Are you vitamin deficient? Could there be any underlying medical issues, like a hormone imbalance or thyroid issue? Are you worried or stressed out more than normal? Most of the time, the body will adjust to a new set of cirstances, but if you miss more than one month, see your doctor.