When you’re not ready to be pregnant, a late period is one of the scariest things in the world to deal with. You start to assume every slight change in your body is its way of telling you that you’re with child. But don’t buy every brand of pregnancy test in the drug store aisle just yet. There are quite a few reasons your period could be late — even if it usually comes like clockwork.
Check out these foods, lifestyle changes and even vacations that can actually disrupt your schedule. However, if your period continues to arrive off schedule for some time, you should probably see your doctor. Any period changes that last more than a month or so should be checked out.

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Stress
If a situation is real enough to occupy your mind most of the time, it’s real enough to make your period late. And if stress really is the problem, your period might continue to be late until you find ways to relax.

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Big Schedule Changes
Did you know that working a new shift at your job is a big enough life change to make your period come late?

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Weight Gain
The more pounds you have, the more estrogen your body makes. If the number on the scale puts you in the obese category, your period may stop in its tracks, come very late, or even last longer.

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Weight Loss
Lose enough weight to be medically underweight and your body might not have enough energy to make the estrogen you need. That can also make your period late, irregular, or stop it altogether.

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Drinking — a Lot
Turn up a lot on vacation or during a long celebration during the wrong time in your fertility cycle and your period may come late, stop sooner than usual or last longer.

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Exercising Too Much
Speaking of vacations, hitting the gym too often can actually make your period come later than usual or stop it completely until you take a workout break.

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Medication
Not every doctor will tell you that a new prescription might delay or stop your period as a side effect. But everything from blood pressure medication to antidepressants can affect your cycle. If you notice a change after a new medication, talk to your doctor to see if what you’re taking might be the problem.

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Traveling
Flying across time zones doesn’t just affect your sleep. It can also make your period come late or change it to a whole new schedule.

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Working With Pesticides
At least one woman who’s spent a summer volunteering or working abroad on a farm that uses pesticides has discovered that working closely with farm chemicals can make your period late and irregular.

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Age
The closer you get to menopause, the less regular your period can be. And since The Change can happen to women as early as their 30s, this one might catch you by surprise.

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Bad Sleep
If your job changes your sleep schedule around, or you just can’t seem to catch any z’s, it can make your period late and irregular until your bedtime becomes consistent.

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Smoking
Women who smoke have more irregular periods than women who don’t. And your period’s schedule can jump around more the longer you smoke and the older you are.

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PCOS
Some changes in your period can suggest a deeper problem. PCOS, also known as polycystic ovary syndrome, affects 10 percent of women and can make your periods painful and irregular. If you also notice acne, extra hair growth and weight gain that you can’t explain, you should bring this up with your doctor.

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Getting Sick
If you get a cold or the flu, it can delay your ovulation and consequently your period. You may not even get one that month. But once you’re feeling better, things should get back to normal.

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Feeling Like Something Is “Off”
If something has been bothering you for a while and you haven’t gotten it checked out, it could also be affecting your period. When diseases and illnesses are left untreated, they can throw your period off schedule or even make it skip months.