So, you want to get your period over and done with now, so you won't have to have it later, while you're on vacation? Tough luck — there aren't quick and easy medicines to induce menstrual bleeding or make your period come faster, in such cases. If you want to delay having a period, however, birth control pills can help you out with that.
Those women who aren't concerned about making their period come out of convenience, but because they're worried about their health, have a different situation on their hands. If you're already sure you're not pregnant but you haven't seen "Aunt Flo" in quite some time, you have a legitimate reason to be worried. What comes next won't surprise you — that's right, it's time to see a doctor!
How A Contraceptive Can Be Used To Induce Periods
Women who have menstruated in their lifetimes but who have not had a period for more than six months without an obvious cause such as pregnancy or lactation suffer from what's called secondary amenorrhea. While short-term amenorrhea may be caused by lifestyle factors such as sudden weight gain or weight loss, stress, and even excessively vigorous physical activity (such as in athletes), a hormonal imbalance or physical factors may also be to blame. If a pituitary tumor or uterine scarring is the cause of absent periods, surgery can help. Hormonal imbalances are, however, often solved pharmacologically. 
Medroxyprogesterone acetate is one such option. It's used for many things, including to treat endometriosis and painful periods, but you'll know it best under the brand name Provera (Depo Provera). Yup, that's "the birth control shot", though the medication is also available as oral tablets of varying doses, and this is what you will be prescribed to help regulate your hormones. 
Combined oral contraceptives (the pill) are also sometimes used to regulate menstrual periods or start them up again, along with estrogen replacement therapy .
Could You Suffer From Thyroid Disease?
Hypothyroid, also called an underactive thyroid or low thyroid, is another possible cause of stopped periods. It tends to cause extremely heavy periods of irregular periods instead, but in some cases periods will stop completely. In these cases, treating the underlying problem can kick start your period again — but not from one day to the next. Rather, you should give it several months. 
Should you be affected by hypothyroidism, you are likely to notice fatigue, weight gain, joint pain, dry skin, thinning hair, a slowed heart rate, and depression in addition to changes to your menstrual cycle. If diagnosed, you'll be prescribed artificial thyroid hormones (levothyroxine) to help your thyroid function normally again. 
Dealing With A Pituitary Tumor
The pituitary gland, located at the base of the brain, is responsible for producing hormones that in turn trigger the production of two of the hormones most crucial to the menstrual cycle — estrogen and progesterone. Though tumors of the pituitary gland are frequently benign, they can cause amenorrhea, the absence of periods. 
If this is the cause of your stopped periods, you may need to undergo surgery to have the tumor removed. Very small, benign, and slow-growing tumors may also be managed medically with Bromocriptine (Parlodel) or cabergoline (Dostinex).  With the proper management of a pituitary tumor, your periods will return to normal as your hormonal function is restored.
Polycystic Ovary Syndrome
Polycystic Ovary Syndrome, an endocrine disorder that causes excess androgen production and multiple cysts on the ovaries, is another possible cause of stopped periods. Other symptoms of PCOS include weight gain, excess hair growth, infertility, pelvic pain, acne, darker patches of skin along skin folds, and insulin resistance. 
Interventions that may help women with Polycystic Ovary Syndrome whose periods have stopped "recover" their menstrual cycles include regular exercise, weight loss, birth control pills to help regulate the menstrual cycle, and also the diabetes drug Metformin. 
A premature menopause (premature ovarian failure) is defined as a menopause that occurs before 40 years of age. Contrary to popular belief, it's sometimes something that can be stopped. Hormone replacement therapy is used to try to make this happen.