Have you had a late period? Or perhaps it's yet to materialise this month at all? While we've been conditioned to think this automatically means we must be pregnant – whether we'd perceive that as good, bad, or neutral news – it's not always the case. In fact, many contributing factors may cause a delayed period.
For starters, many of us don't quite understand what constitutes a ‘late’ period. Thanks to the rise of period tracking apps, it's easier than ever to know when we're due on and, crucially, when we're running a little behind schedule. But it's important to understand that it's totally normal for your cycle to vary by up to seven days, so a period shouldn't necessarily be considered ‘late’ until it's been at least a week.
GLAMOUR spoke to Dr Claudia Pastides (MRCGP, MBBS), Medical Advisor at Flo Health, who further advised that a “normal” menstrual cycle isn't strictly limited to 28 days, as many of us are led to believe. In fact, your cycle can be between 21 to 35 days and yes, it's normal for your cycle length to vary a little bit from month to month.
However, Dr Pastides adds, it's also important to note that “frequent variation of more than seven days between cycles = an irregular cycle and should be checked out with your GP.” Also, if you've gone three months without a period, this should be checked out by a doctor.
Even if your menstrual cycle has traditionally run like clockwork.
Reasons why your period might be late (other than pregnancy):
Seriously, in what way does stress not negatively affect us? Yes, it even affects our periods. When we’re very stressed, the part of your brain that’s responsible for producing hormones that are vital to reproduction and your period are knocked out of kilter. This means your periods are likely to be delayed, if not totally stop, until you’re in a calmer state.
Dr Pastides advises, "If you skip three periods in a row, regardless of stressful circumstances or not, it is best to see your GP about it and look into it, and not automatically put it down to the stress you are under.
“If your delayed periods are stress related, it is a good idea to speak to someone about it and get advice from your doctor to see what you can do to help. Long term stress is bad for more than our menstrual cycles, it is bad for mental health and the rest of our physical health too.”
Don’t worry, going to a yoga class or going to the gym twice a week isn’t going to affect your period, but if you’re putting your body under extreme pressure – say training for a marathon – it can have a knock on effect. If your body feels you’re exerting too much energy it will “switch off” what it temporarily deems a non-essential function like periods. Once you relax the exercising, your period should return as normal.
Explaining why this happens, Dr Pastides notes, “Exercising too much (often defined as strenuous exercise that burns more calories than you take in) can cause ovulation — and therefore your period — to stop.”
Again, if you think your activity levels could be affecting your period, it's advised to check in with your GP.
Certain types of medications will trigger your body to stop periods. Some contraceptive pills and antidepressants are known to affect your cycle due to hormone levels being disturbed. It's always recommended to speak to your GP about possible side effects.
Dr Pastides explains that the morning after pill can also have an effect on your cycle: "Emergency contraception pills can make your next period arrive later than expected. But if it’s more than seven days late, you should take a pregnancy test.
“Also, if you’ve had an intrauterine device (IUD or coil) fitted (either as emergency contraception or for contraceptive purposes), changes to your cycle are possible. Some people who have a hormonal IUD notice their periods actually stop entirely over time.”
One study estimates that women with PCOS are roughly eight times more at risk of suicide.
Gaining or losing a couple of pounds won’t have a drastic effect on your periods but if your weight fluctuates dramatically it could. Your body needs a certain amount of body fat to ovulate so if you drop weight very fast, it will stop your period. Equally, if you put a lot of weight on, an increase in fat cells can raise oestrogen levels which could stop your body from releasing an egg and therefore miss a period.
Dr Pastides notes, "It’s natural for our weight to fluctuate, but a significant change is a known cause of late, missed, and stopped periods, as are the effects of eating disorders like anorexia and bulimia.
“How much weight loss is “significant” enough to affect your period? Some small studies have determined it to be more than five percent of your body weight in a month, but more research into this is needed and, of course, this is very much an individual thing.”
If you’re worried about your own or someone else’s health, you can contact Beat, the UK’s eating disorder charity, 365 days a year on 0808 801 0677 or beateatingdisorders.org.uk.
If we become ill – say with the flu or a tummy bug – this can cause stress on the body, which can delay ovulation. Dr Pastides points out that even “so-called ‘minor illnesses’ can cause stress on the body and this stress can throw off your cycle and delay your period.”
Whether you’re jet lagged or are a shift worker, if you have a change in your sleep pattern it will cause delays due to your body clock and rhythm being disrupted. Dr Pastides notes, "When you pass through different time zones, your sleeping pattern may change and your cycle can change too, due to a change in your circadian rhythms, which regulate your cycle and hormones.
“If, for example, you move or travel to a different time zone and start working during the hours when your body is used to being asleep, your period can be thrown off. But it will usually readjust and become regular again within one or two cycles.”
A skipped or irregular period could be a sign that you have a medical condition if it persists. Dr Pastides tells GLAMOUR:
"Polycystic ovary syndrome (PCOS) and thyroid disease are common reasons for irregular periods. PCOS affects around 10% of women and occurs when high levels of androgens (a type of hormone) cause fluid-filled sacs, or cysts, to grow in the ovaries. In turn, this interrupts ovulation and causes irregular and stopped periods. Other symptoms of PCOS include excessive facial or body hair, acne, oily skin, weight gain and thinning of hair.
"When it comes to the thyroid – both overactive and underactive thyroid can throw off your period. Symptoms of hyperthyroidism (overactive thyroid) include anxiety, irritability, diarrhoea and mood swings. And for hypothyroidism (underactive thyroid) you may also notice weight gain, tiredness, low mood and constipation.
“If you notice symptoms of thyroid problems or of PCOS, together with frequently delayed and irregular periods – it is good to see your doctor, as there is treatment that will help.
“We’ve got some great PCOS resources in the Flo app, with more information about this condition.”
If you are concerned about having a late period, it's always recommended to book an appointment with your GP to discuss diagnosis and treatment. You can find your local GP here.
Women have been urged to delete their period tracking apps.
