My period is always on time – always! – but a few weeks ago, when I went on vacation, overseas, I found myself panicking. My period was late. And not only by a few days, but over a week late.

I knew I wasn’t pregnant, but the idea of having a baby completely scared me. Like most of you, pregnancy is a life-changing event and one of the scariest experiences if you’re not planning on having a baby anytime soon. I mean, having a baby is a game changer (and really expensive too boot.)

Fortunately, my period came and went, and I realized it was all the stress and the few extra pounds I had put on, due to the holidays and yummy holiday food I was binging on, and my oversea travels that threw my body for a loop. I went 52 days from one period to the next – so it definitely freaked me out!

So why is your period late? What might cause late periods?

Pregnancy is the most obvious answer. And you should always take a home pregnancy test – you can pick them up pretty cheap these days from the dollar store, or your local grocery store.

Here are the most common reasons for a late period – or skipped period when you aren’t having a baby.

1.) Changes in your Weight

Have you checked the scale recently? Have you lost weight, or gained a few pounds? Any changes in your normal weight – either from gaining or losing pounds – can have have an effect on your ovulation cycle. Weight changes can affect your estrogen level, and may cause you to have late period, or no period at all.

Skipping a period shouldn’t stress you out too much, but if you skip three months in a row, definitely schedule a visit to your OB/GYN.

In my case, I had put on a couple of pounds – probably from over Thanksgiving and Christmas, and my body freaked out, since my weight has been the same for the past 5 years.

2.) Are you Stressed?

Have you been really stressed? At work, or in your personal life? Stress and your emotions can play a role in the health of your body.

Has something traumatic, or upsetting event occurred in your life? Possibly a death in the family, fear of losing your job, a recent breakup .. or maybe you moved recently. Any life event that is causing you stress, anxiety or any other influx of hormones and feelings can affect your menstrual cycle and throw it off balance.

3. Traveling and Jetlag

Traveling, changing time zones, and jet lag can also throw your body in a loop, especially if you’re going on an overseas trip. When your circadian rhythm – your body clock – gets messed up, even temporarily, it can can affect other areas in your body. Your jet lag, or the fact that you are traveling and your schedule is different may cause you to skip your period, or cause your period to come later than it was supposed to.

4. Change in Lifestyle Habits

A sudden change in your lifestyle – for example, you started working out or exercising, when you normally live a sedentary life – can also mess up your periods and cause late periods.

Exercise and fitness, especially when you are over do it, are very common culprits for causing period problems.

5. Your Thyroid

It could be your thyroid. Thyroid imbalances, hypo or hyper, can affect your period. Though your thyroid is located in your neck, it has many important functions in your body, besides regulating your metabolism.

Hypothyroidism is a very common cause of menstrual cycle irregularities. Women with hypothyroidism can skip periods, or have very infrequent periods. (They can also have frequent and heavy periods too.)

6. Celiac’s Disease

More and more people are going gluten-free these days. Celiac’s disease, an autoimmune disorder in which people cannot digest gluten, can also cause menstrual problems. There’s a growing body of research that suggests that untreated celiac disease can cause period problems, including skipped and late periods, early onset menopause, and even cause secondary amenorrhea – the temporary (and sometimes permanent) stopping of your period.

The reasons for celiac disease causing reproductive problems isn’t well understood yet. There needs to be more research, but it is possible that if gluten is making you sick, that you could have Celiac’s disease, and this could be the reason that you are missing your period.

7. Hormonal Imbalances

Hormonal imbalances in your body, including polycystic ovary symptom (PCOS) can also be to plane. PCOS can cause you to skip your period, or just not have your period very regularly.

In addition to PCOS, early menopause – which can occur in women in their 30s – can also be to blame for your late or skipped periods.

If You are Worried …

There are so many other reasons you could miss your period – including rare tumors and other health problems.

In a majority of cases, however, you are missing your period, or your period is late because you are pregnant. Take a home pregnancy test to be sure.

If your period still doesn’t come (and skips for more than three months), you should make an appointment with your doctor to figure out what’s going on.

If you ever feel like something in your body is not right, go see a doctor! Good luck!