While you can get pregnant without having a period, it’s not likely. In fact, if you’re not getting your periods, this is a good reason to see your gynecologist. There are some normal—and some not-so-normal—reasons this can occur such as breastfeeding, medications, being underweight, birth control, and more.
The key is to find out why your periods have been absent and what you can do about it. Read on to learn more about amenorrhea (or the lack of a period) including why you may not be having regular menstrual cycles and what can be done about it, especially if you want to get pregnant.
Your Period and Getting Pregnant
Your period is the most obvious sign that your body’s reproductive system is at least trying to operate. It marks the end of one menstrual cycle. The female reproductive system is complex, but here is a quick and simple breakdown of what happens every month (if you’re getting your periods).
- At the start of your monthly cycle, specific hormones tell your ovaries to start developing an egg. The egg, or oocyte, is contained inside a follicle. This follicle is like a tiny bubble. It contains fluid, nutrients, and the immature egg.
- For the first half of your cycle (about 12 to 14 days), the hormones stimulate the follicle and egg to grow. Eventually, the egg reaches maturity.
- Halfway through your cycle (at about day 14, though this can vary). the follicle bursts open, and the egg is released from the ovary. This is called ovulation. The egg only lives for 12 to 24 hours.
- For the second half of your cycle (days 15 to 25, approximately), after ovulation, the hormone progesterone triggers the lining of your uterus to prepare for a fertilized egg, or embryo. The lining of the uterus is called the endometrium. During this time, endometrium will build up, becoming thicker and changing its physiological structure to be just right for an embryo.
What happens next depends on whether you have have had sexual intercourse within five days of ovulation. If you have, there may be sperm waiting in the reproductive system. Sperm can survive in the female reproductive system for up to five days. Sexual intercourse on the actual day of ovulation, and even the day after, can also lead to conception. If a sperm cell fertilizes the egg, you will become pregnant.
If you conceived, an embryo will implant itself into the uterine lining between seven and 10 days after ovulation. This will trigger different hormones to prepare the body to nurture a pregnancy.
If you didn’t conceive, the hormone progesterone will begin to drop. Lowering levels of progesterone will eventually signal the endometrium to break down and expel itself. This is your period.
As the endometrium is expelled, your body starts releasing hormones to trigger the next month’s ovulation, assuming you’re having regular cycles. Your period marks the ending of one cycle.
If you get your period, it is likely (but not certain) that you ovulated within the past two weeks. Ovulation is required to get pregnant. If you’re getting your periods regularly, you are most likely ovulating regularly.
Can You Ovulate Without a Period?
If you are not getting your periods, you are probably not ovulating regularly. There are a number of reasons this may occur (more on that below). However, this doesn’t mean you won’t suddenly ovulate without getting a period first.
As mentioned above, menstruation marks the end of one cycle. If ovulation occurs, and you don’t conceive, you will get your period. But let’s say you are currently not having regular cycles. You could, depending on the reason why you’re not menstruating regularly, suddenly start a menstrual cycle.
The end of your cycle is marked by your period starting, but there are no obvious signs that your body has begun a cycle. You can ovulate and not know it.
You will only know you ovulated if you get your period or, if you had sexual intercourse within your fertile window, you get pregnant. You may not realize you’re pregnant for a while, though, since you haven’t been getting your periods. You won’t have a period to be “late” if you haven’t been getting one.
Why You May Not Be Getting Your Period
The medical term for a lack of menstrual cycles is amenorrhea. It can have many causes.
Pregnancy
If you have had regular periods, and then suddenly stop getting your period, you may be pregnant. This is likely the first thing you thought of when your period was late, and you have likely already taken a pregnancy test.
But what if your pregnancy test was negative? Could you still be pregnant? Yes. It’s unusual, but it is possible to be pregnant and get a negative pregnancy test. See your doctor for follow-up and confirmation, and until you know otherwise, act as if you’re pregnant (avoid alcoholic drinks, for example).
Breastfeeding
Exclusively breastfeeding a baby can prevent your periods from coming. How long will you go without a period when breastfeeding? It depends on how often you are breastfeeding and your personal biology.
Birth Control
Some forms of birth control can stop your periods. Your doctor should have told you if this was possible when they prescribed it.
If you want to try to conceive, how long will it take for your periods to return after you stop taking the birth control depends on your body and your contraception choice. With Depo-Provera, also known as the “birth control shot,” menstrual cycles tend to return about six months after the last injection (if you were receiving the injections for at least one year).
Other Medication
Birth control isn’t the only medication that can stop your periods. Other medications that may stop your cycles include some psychiatric drugs, chemotherapy, allergy medications, and blood pressure pills.
Obesity
Obesity is one of the most common causes of infertility. Women who are obese may experience irregular menstrual cycles and, in some cases, their periods may stop completely. Losing weight may restart or regulate your cycles.
Underweight
With obesity, too much fat throws off the normal hormonal balance in the body. If you are underweight, the lack of fat can throw your reproductive cycle off. If this is the problem, bringing your weight up should restart your cycles.
Exercise or Lack of Body Fat
You may be an athlete who is neither over- nor underweight (based on body mass index). However, it’s not your weight that really impacts your reproductive cycle—it’s the amount of fat.
Athletes may have a high percentage of muscle and a low percentage of body fat. This can cause their menstrual cycles to be irregular or even stop completely. Excessive exercise can also cause your periods to become irregular or stop.
Stress
Stress can cause you to skip a period or two. However, it’s highly unusual for stress alone to cause your menstrual cycle to stop for months.
PCOS
Polycystic ovarian syndrome (PCOS) is a common cause of female infertility. One of the primary symptoms of PCOS is irregular or absent periods.
Primary Ovarian Insufficiency
Also known as premature ovarian failure, primary ovarian insufficiency (POI) can cause irregular or absent periods. Sometimes, a person with POI will go months or even years without a period, only to have them restart without explanation. POI also used to be called “early menopause,” but that's misleading. After menopause, menstruation never returns.
Hormonal Imbalance
While PCOS and POI can cause ovulation problems, so can other hormonal conditions. Athyroid imbalance, endometriosis, an underlying untreated medical condition (like diabetes), and hyperprolactinemia can lead to irregular or absent periods.
Uterine Problems
Structural problems or scarring of the uterus can cause your periods to be irregular or stop completely. This may occur after a dilation and curettage (D&C) or uterine surgery.
Menopause
This is sometimes the first fear women have when they suddenly stop getting their period, even if they are years and years away from it becoming a reality. While early menopause is possible, unless you are 45 years old or older, it’s unlikely menopause is the cause for your lack of periods.
If You Want to Get Pregnant
Doctors usually recommend trying to conceive for one year (or six months, if you’re age 35 or older) before getting a fertility evaluation. However, this doesn’t apply if you have signs or symptoms of a fertility problem. That would include amenorrhea.
If you’re not getting your periods, you may be dealing with infertility. Make sure that you and your partner are evaluated. There may be more than one reason you aren’t conceiving, and male infertility is more common than you may realize.
Depending on why you aren’t ovulating, and if there are other fertility problems, treatment possibilities include lifestyle change, weight loss or gain, or medication change. You may also need treatment for an underlying medical condition, or fertility treatments.
If You Do Not Want to Get Pregnant
If you don’t want to get pregnant, you shouldn’t rely on your lack of menstrual cycles as birth control. This is true even if you’ve been previously diagnosed as infertile (unless your doctor tells you otherwise).
As mentioned above, depending on why you’re not getting your periods, it’s possible to ovulate and not get a period first as an indication that you’re fertile again. Talk to your doctor about the best contraceptive choice for you.