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When your period Spidey senses start tingling (aka you’re crampin’ real bad) you know it’s about to get ugly in your nether regions. Ah yes, you’re period is coming and it’s going down like the Red Wedding.

But, what if your monthly flow comes back way before it’s next scheduled appearance? Unfortunately, it is possible to have two periods in a month. Here’s why.

You get your monthly gift (the gift you never wanted) about every 28 days when your body doesn’t get pregnant. In health speak, basically the egg your ovary releases each month isn’t fertilized by sperm so your uterus sheds its lining to start over for the next “will we get pregnant?” waiting game.

It’s totally normal for a menstrual cycle to range anywhere between 21 to 45 days. Our bodies are all different so it’s extremely unlikely to have the perfect 28-day cycle.

As for the actual period part, it usually lasts between 2 and 7 days. Anything more than a week is called menorrhagia and is considered abnormal. Bleeding longer than a week, especially if it’s really heavy, can lead to anemia and other issues you’ll want your doctor to be aware of.

If the crimson tide is rolling in for the second time this month, there is definitely something going on with your bod. Most likely what you’re experiencing isn’t a second period at all, but breakthrough bleeding or spotting between your periods.

Here’s what your vagina might be trying to tell you.

1. Birth control

If you’re on the pill or another form of hormonal birth control like an IUD, and extra visit from Aunt Flow is pretty common. According to a 2016 contraception study, irregular bleeding is a big reason 46 percent of women who are dissatisfied with their birth control stop using it.

If you’re new to hormonal birth control your changing hormones can lead to extra bleeding. Some women always experience spotting between periods while on the pill.

Forgetting to take your BC or taking the pill at different times each day can also lead to spotting. If you just went off the pill, you could also experience additional bleeding as your body tries to adjust to your new hormone levels. It could take a few months for your cycle to get back to normal.

2. Pregnancy

If you have a little passenger aboard the preggo train, you can experience spotting that looks like a light period. When the fertilized egg implants in your uterus it can kind of burrow in there and cause bleeding.

Implantation bleeding usually looks brown or pink in color and will only last from a few hours to about 3 days.

3. Ectopic pregnancy

Unlike normal pregnancy, an ectopic pregnancy happens when the fertilized egg attaches in the wrong place (outside the uterus). This usually happens in the fallopian tubes, and can be life threatening.

According to the American Pregnancy Association, 1 out of 50 pregnancies are ectopic. Call your doctor immediately if you have heavy bleeding with sharp or stabbing pain (pelvis, abdomen, shoulder, or neck), GI issues, dizziness, or fainting.

4. Miscarriage

Losing a pregnancy can also cause unexpected bleeding. If you find this second period is unusually heavy and is accompanied by cramping in the lower abdomen or back, you could be experiencing a miscarriage.

According to the Mayo Clinic, roughly 10 to 20 percent of pregnancies end in miscarriage when the mother knows she is pregnant, meaning many women who miscarry (usually before week 12) never even knew they were pregnant to begin with.

4. Fibroids

A heavy, painful period or bleeding between periods (hello, second period) is a sign you have fibroids. Fibroids are non-cancerous tumors that grow on the uterine wall.

Very, very rarely are fibroids cancerous. The Office on Women’s Health notes that 20 to 80 percent of women have fibroids by the time they’re 50 years old. However, fibroids are more common in your 40s and early 50s.

5. Cysts

Similar to fibroids, ovarian cysts can cause a bonus period. When these fluid filled sacs form on an ovary, they can produce hormones that mess with your menstrual cycle. Most cysts don’t cause problems, but if they’re too large they can push on the bladder or rupture.

6. PCOS

Polycystic ovary syndrome (PCOS), which occurs when there are a bunch of small cysts in the ovaries, can also lead to an extra episode of Shark Week. A woman with PCOS also produces extra testosterone that prevents the egg from developing properly.

According to the Hormone Health Network, 7 to 10 percent of women in their baby making years have PCOS, and the syndrome is the most common culprit for infertility.

7. Endometriosis

No one really wants to join the endo club (sup, Julianne Hough), but if you’re having an “extra period” it could be endometriosis. Women with endometriosis have tissue growing outside the uterus that is similar to the uterine tissue (the endometrium).

According to the Mayo Clinic, this tissue thickens, breaks down and bleeds just like the uterine wall would normally, but it’s trapped elsewhere in the body like the ovaries, fallopian tubes, pelvic tissue, or intestines.

Endometriosis can cause severe pain, scar tissue, adhesions and fertility issues.

8. Sexually transmitted infection (STI)

Usually if anything strange is going on down below, STI’s are the first thing that come to mind if you haven’t been careful. STI’s cause a bunch of unpleasant symptoms, including bleeding.

If you’re experiencing a lot of pain in your nether regions accompanied with cold symptoms and weird discharge, you could have an STI.

Note: While not technically an STI, pelvic inflammatory disease (PID) is usually a result of bacteria getting into your lady bits from sexual intercourse, especially from gonorrhea or chlamydia infections.

PID can cause extra bleeding, especially while or right after you’re getting it on, as well as lower abdominal pain, vomiting, smelly discharge, and fever.

9. Thyroid issues

Your thyroid creates a hormone that helps your entire body work right, including your menstrual cycle.

If your body makes too much thyroid hormone (hyperthyroidism) or too little thyroid hormone (hypothyroidism), you can have irregular periods (hello, second period!) as well as light or heavy periods.

10. Early menopause

The “change” isn’t supposed to show up until you’re middle aged, but it can happen early. The Cleveland Clinic notes about 1 percent of women under 40 and 5 percent under 45 go into early menopause (dang you genetics!).

If you’re experiencing premature menopause, your periods can become irregular and you’ll have standard menopause symptoms like hot flashes and mood swings.

11. Stress

If you’re stressed out of your mind, your body takes a huge hit. It’s way easier to get sick and it can also mess with your cycle.

A 2015 study of 100 female medical students found that high stress levels are associated with irregular cycles. If you’re stressed, you could have extra bleeding or lose your period altogether.

12. Weight gain or weight loss

Gaining or losing a few pounds is unlikely to alter your cycle. But, if you gain or lose a lot of weight fast, you could eff up your flow. Crazy weight changes mess with your hormones, which is the captain of all your period woes.

You can also look at your flow to get an idea of what is going on with your body during your period. Like our cycles, our periods are all pretty different and can even differ with each day, hence the slim to supersize tampons and pads.

Depending on where you are in your cycle, your period can be bright red, dark red, pink, or brown. You can also experience some clots, which is normal as long as it’s not bigger than a quarter.

Spotting on the other hand is usually extremely light in terms of flow and is typically brown or pink in color.

Discharge or cervical fluid (also called mucus, but we’ll spare you from reading that word again) is also completely normal throughout your cycle and is an indicator of how fertile you are.

UNC School of Medicine outlines cervical fluid as anything from clear wet, creamy, white, yellow, or transparent and stretchy like an egg white. Discharge out of this realm is a signal that you have an infection or other health issue.

According to the Cleveland Clinic, discharge that makes you itch or swell, smells bad, or looks foamy, chunky like cottage cheese, green, yellow (different than usual), or gray is a sign you have an infection.

This could be anything from a yeast infection (chunky) to an STI so give your doc a call if something weird is going on.

If it looks like a double feature of Carrie for months at a time, and you’re experiencing heavy bleeding, unusual discharge, or pain, it’s time to call the doctor.

Remember when we mentioned how abnormally long, heavy, and extra periods can lead to anemia? Well, being anemic can lead to a ton of health problems.

Call your doctor if you have lower abdominal pain, feel super tired or weak, and you’re experiencing a heavy period (we’re talking using a tamp or two every hour) with clots the size of a quarter.

Additionally, pain and weird discharge could be a sign of an STI that needs immediate treatment or a chronic disorder that needs attention.

If possible, before you visit the doctor, track your symptoms and your extra period days to help you get to the bottom of the issue.

tl;dr

  • The average period is 28 days, but anything between 21 to 45 days can be totally normal. Everyone is different!
  • A second period is usually breakthrough bleeding or spotting between your periods.
  • Your period can be bright red, dark red, pink, or brown in color.
  • Extra visits from Aunt Flow could be from hormone changes, disease, or infection.
  • Call the doctor ASAP if you have two periods for months in a row or any unusual pain or discharge.