Uh-oh! Your period is late. Safe to assume you’re probably pregnant, right? Wrong. If you’ve taken a pregnant test and the results are negative, then all signs point to wonky hormones or other factors negatively impacting your health, like fibroids, a thyroid disorder or STDs. To help explain why some women’s periods go rogue, particularly when a pregnancy has been ruled out, is OB/GYN Dr. Lydia Mayida of Detroit Medical Center’s Hutzel Women’s Hospital.“Having your period regularly is usually taken for granted until you experience the worry that comes along with a delayed or missed menstrual cycle,” Dr. Mayida shares with ESSENCE. “A regularly occurring menstrual cycle is often considered a sign of good health and, when it doesn’t come, it’s easy to quickly jump to life-changing possibilities such as an unplanned pregnancy.”But, as Dr. Mayida points out, there are many other causes of a missed or delayed period that aren’t related to pregnancy or an underlying disease. Below, she outlines five specific reasons your period is late or a no-show this month:1. The birth control method you’re using:While it’s true that birth control reduces your chances of getting pregnant, certain methods can also “make your period disappear through their mechanism of action.” Your body’s hormones are essentially being regulated by the contraceptive, which may cause your period to decrease or disappear altogether. 2. The side effects of the medicine you’re taking:Drugs, whether those prescribed by a doctor or those of the street variety, can cause delayed periods or irregular menstrual cycles. If you’ve started taking new medication, Dr. Mayida says the side effects of different forms of medicine can “interfere and be a potential cause of a missed or late period.”3. Excessive stressBy now, you’ve probably heard of the word “cortisol” aka the stress hormone. Over time, a build up of stress or the cortisol hormone can suppress the very hormones you need to reproduce. If the uterine lining doesn’t shed, your period could be delayed. 4. Intense ExerciseDr. Mayida adds that extreme physical exertion can interfere with the body’s reproductive system, causing a late period. This is especially common among professional athletes who miss their periods when their body fat percentage drops. “Intense exercise has the ability to alter your hormones, and this can cause delayed or miss periods,” says Dr. Mayida. 5. DietingThe food you consume also has a direct impact on the body, including your hormones. “Excessive starvation or dieting that causes significant weight loss may also make your periods disappear,” says Dr. Mayida.That’s why some women who have opted to go vegan or who have switched back to meat after being vegan often report they have irregular monthly cycles. Foods high in sugar or carbohydrates can alter the female sex hormone estrogen, affecting your period. The same thing can happen when the body doesn’t get enough protein. On the flip side, gaining too much weight can negatively affect reproductive hormones. However, Dr. Mayida does point out that other factors could be at play when your period is MIA. “There are underlying diseases and conditions that may affect period irregularity, such as polycystic ovarian syndrome(PCOS), thyroid disease, hyperprolactinemia or premature menopause,” explains Dr. Mayida. In addition to these hormonal imbalances causing you to miss your period for three months, Dr. Mayida informs us that “sudden abnormal hair growth on the chest and face, excessive weight gain or loss or discharge from the breasts” could also be clear indicators that you’re suffering from a more serious condition. If you’ve noticed any of these signs, Dr. Mayida advises that it’s important to seek medical attention or book an appointment with your gynecologist.