Late Period But Not Pregnant? Here Are Some Possible Reasons Why

So your period is late and you’re definitely not pregnant - what’s up with that? There can be a number of different reasons why your period is late that have nothing to do with pregnancy, and these can be good indicators of what else is going on in your body. 

Menstrual cycle lengths vary from person to person, with the average being from 21 to 35 days. You should track your cycle to determine what’s considered ‘normal’ for your body (period tracker apps are great for this) and to work out if your period is running late or on time. If you do notice your period is late, here are some possible reasons why:


Changes in your body weight

Low body weight and obesity can both impact your menstrual cycle, as can rapid weight loss. Low body weight and severely restricted food intake can be especially problematic when it comes to missed periods and fertility issues, as it affects your body’s ability to create sufficient reproductive hormones. If you’re struggling with your weight, be sure to speak with a doctor and/or dietician to help get back on track or diagnose any underlying conditions. 



Polycystic Ovarian Syndrome or PCOS is a very common and frequently undiagnosed condition caused by an imbalance of reproductive hormones. As PCOS affects your ability to ovulate, it can lead to late or irregular periods. Learn more about PCOS symptoms and treatment options in this article. 



Stress can have profound effects on the body, and especially the menstrual cycle! And it can come from many different places in life - whether it’s work or school, our relationships, stressful events like moving house or even travel. When you’re stressed out, ‘fight or flight’ mode is activated and your brain sends signals to your body to shut down non-essential functions (like reproduction) to escape the perceived threat. Of course, in this day and age the stress we face is rarely from being chased by predators, but our body is still programmed to react this way. If you’re feeling stressed out, try bringing some relaxing practices to your day like yoga, meditation or deep breathing, and be sure to reach out for help from family, friends or a professional if you feel yourself struggling. 


Changes in your exercise routine

That new commitment to more intensive exercises like Crossfit or long distance running can definitely contribute to your late or missing period. In fact, it is quite common for athletes to experience missing periods (or amenorrhea), due to the body burning excessive calories during exercise with not a lot leftover to maintain a functional reproductive system. Pay attention to how your body responds to your new exercise routine and consider taking it a little easier if you want to maintain a healthy menstrual cycle.


Changes to your birth control

Hormonal birth control like the pill can help keep your periods regular, but there is often an adjustment period where you may experience missed or late periods. This is usually normal for the first few months, but you should consult a doctor if you are concerned. Other birth control methods like the IUD, implant or contraceptive shots like Depo Provera can also cause irregular periods, or your period might stop altogether. 



For those in their 30’s or 40’s and beyond, perimenopause can be a reason why your period is late. This is the stage before full menopause occurs, and it can last several years. Signs that you may be in perimenopause can include irregular periods, hot flushes, breast tenderness or worsening premenstrual syndrome (PMS). You can read more about the stages on menopause and what to expect here. 


Thyroid issues

Your thyroid is a butterfly shaped gland located in the front of your neck that regulates your body’s metabolism and can affect your hormones. Conditions like hypothyroidism (an under-active thyroid) or hyperthyroidism (and over-active thyroid) can result in late or irregular periods. If you’re experiencing other symptoms of thyroid issues such as anxiety, brain fog, heart palpitations, unexplained weight loss or gain, fatigue, hair thinning and insomnia, see your doctor to investigate.

Staying prepared and protected when your period is late

There’s nothing worse than that feeling of uncertainty about when your period is going to arrive, especially if it’s late - the last thing you need is stained clothing or being stuck without a stash of period products and having to make a mad dash to the shops. If you’re expecting your period to start soon, it’s a good idea to wear some absorbent and leak-proof period underwear in place of your regular undies. It doesn’t feel like you’re wearing a pad and your clothes will always be protected, even when you feel your period start in the middle of an important meeting or exam (yikes!). And of course, always keep your clean JuJu menstrual cup in your bag for anytime your period takes you by surprise! 

Late periods - what should you do?

While it’s normal for your period to be a few days early or late from time to time and through life’s up and downs, if your periods are very irregular or are few and far between, it’s a good idea to get checked out by your doctor to see if there is an underlying cause that needs treatment.