Over 90 percent of women say they get some premenstrual symptoms, which can range in intensity from mild to severe and often include headaches, fatigue, cramps, moodiness, insomnia, and tender breasts.

But what happens when your period symptoms flare up, you’ve got your tampons ready to go, and then no period shows up? The reflex reaction for most women is to think that they must be pregnant. Even if you haven’t had sex in weeks, it’s easy to go straight to that thought.

While it can be alarming if you weren’t planning on having a baby, pregnancy is only one of the possible reasons that you could be having period symptoms but no blood. If you are pregnant, implantation occurs at roughly the same time your period would come normally. The symptoms? Almost identical to those you have right before you get your period. It can seem like a cruel joke, but the similarities are just your body’s way of processing fluctuating hormone levels.

But before you run to the store for a box of pregnancy tests, call your mom and your best friend, and figure out how you’re supposed to have a successful career and a baby (it can be done!), explore what else could be happening in your body. There are several reasons that periods go rogue.

Polycystic ovary syndrome (PCOS).

PCOS affects 1 in 10 women of childbearing age, and is a disorder that causes hormonal imbalances. If you have PCOS, your ovaries produce more androgen (called a “male hormone,” even though females produce it too) than normal. Coupled with possible clusters of small, fluid-filled cysts on your ovaries, these high levels of androgens affect the release of eggs during ovulation and can make your period go MIA. If you think you might have PCOS, it’s important to talk to your doctor. While there aren’t any cures, a proper diet and fitness routine can ease some of the symptoms.

Other possible signs of Polycystic Ovary Syndrome: Abnormal periods, excessive hair growth, and rapid weight gain.

Anemia.

Iron deficiency, or anemia, is common in women of reproductive age. This is often due to not consuming enough iron, heavy periods (ironically, since a side effect of anemia can be no period at all), or an inability to absorb iron properly. If your body doesn’t have enough iron, it can shut down your menstruation process.

Other possible signs of anemia: Fatigue, dizziness, headache, and irritability.

Physical or psychological stress.

Though some stress can help you challenge yourself, too much can have a negative impact on your health. While we don’t know much about the relationship between stress and periods, we do know the hypothalamus controls the pituitary gland, which controls the thyroid, adrenal glands, and ovaries. All of these factors work together to manage the hormones that affect your menstrual cycle—estrogen, progesterone, follicle-stimulating hormone, and luteinizing hormone.

Stress can throw your hormone levels off and, as a result, leave you with period symptoms but no period. If you’re feeling stressed, take some time to learn coping mechanisms, rest, and reset your body and mind.

Other possible signs of stress: Fatigue, change in libido, upset stomach, insomnia.

Nutritional imbalance.

Too much junk food, caffeine, and alcohol can do more than just tempt you to miss your cycling class. It can also wreak havoc on your reproductive system. Experiencing period symptoms but no blood can happen when your hormones become imbalanced. This imbalance can be due to a poor diet, excessive caffeine consumption, or heavy drinking. Gaining weight or losing weight can be attributed to a lack of proper nutrition, which can also affect your menstrual cycle. To make sure you’re getting the nutrition your body needs to function properly, make sure you’re eating plenty of vegetables, healthy fats, and whole carbohydrates.

Other possible signs of a nutritional imbalance: Unusual food cravings, constipation, sleepiness, poor concentration.

Rigorous exercise.

Naturally, women carry more fat than men do. While it can seem unfair, this fat is necessary to help regulate your hormones and support your reproductive system. An intense exercise program may throw your hormones off balance and cause you to miss your period. Unless you’re exercising too much and not getting enough nutrition, this is likely just temporary. Once your body adjusts to your new lifestyle, your period should return.

Other possible signs of too much exercise: Irritability, low energy, early onset muscle fatigue.

Birth control.

Whether you’re on the pill, have an IUD, or have chosen another form of birth control, the hormones present are very likely to affect your menstrual cycle—at least temporarily. With all birth control, there is a period of time where your body works to acclimate to the new hormones. This can happen for several months, causing you to miss periods while still having period symptoms. You may also miss your period is if you skip the sugar pill or are on seasonal birth control.

Other possible signs that birth control is causing your missed period: Extended use of birth control, changing contraception, and stopping birth control.

There are many reasons why you could be experiencing cramps, fatigue, cravings, and other period symptoms but no actual period present. Most of these causes are temporary and can be fixed with some simple lifestyle changes like eating healthier, allowing time for your body to adjust to new workout routines and contraception, and easing the stress in your life. It’s important to note that if you have any concerns about your missed period or if you don’t menstruate for a few months in a row, you should always talk to your doctor.

FEATURED IMAGE BY AVERIE WOODARD