When it comes to preventing pregnancies and treating certain other issues, hormonal birth control is a very popular choice. Birth control options include:

Among these options, pills are used by sexually active women in the United States.

All forms of hormonal birth control work by preventing the ovaries from releasing an egg every month and by thickening the body’s cervical mucus at the opening of the uterus. Together, these prevent a female’s eggs from being fertilized.

Many forms of hormonal birth control are either inserted into the vagina, injected into the skin, or taken by mouth. The latter includes “extended or continuous use” birth control pills. These are taken orally every day to help prevent unwanted pregnancy.

However, a few types of birth control only give the body 21 days of hormones and allow for one week of no hormones. This is the case with birth control patches, vaginal rings, and 21-day combined pills.

Patches are usually reapplied once a week for three weeks, and then aren’t worn for one week. A vaginal ring is worn for three weeks, and then taken out during a fourth week. Similarly, after taking three weeks of combined pills, you may either not take any pills or begin taking “placebo” pills. The placebo pills don’t contain hormones.

During your break week, you’ll experience something called withdrawal bleeding. This bleeding is similar to the regular menstrual period you would get if you weren’t using birth control patches, rings, or pills.

There are many birth control options on the market, but only certain hormonal birth control has the potential to cause withdrawal bleeding. Here’s an overview of the most common hormonal birth control options:

Injections

  • Injections that contain progestin include the Depo-Provera shot, which must be taken once every three months, and the Nexplanon implant, which lasts up to three years.
  • They don’t cause withdrawal bleeding if taken continuously as prescribed.
  • You may still have irregular bleeding and spotting.

Intrauterine devices (IUDs)

  • Hormonal IUDs that contain progestin last about three to five years. They may result in no period or a light period after being inserted. The timing of periods can be irregular, especially right after the IUD is placed.
  • Copper IUDs last about 10 years. These are hormone-free, so your body will cycle through periods just like it did without the IUD. Some women notice a slight increase in menstrual flow for the first year after having the IUD placed.

Patches

  • Patches that contain estrogen and progestin are reapplied every week for three weeks, with an optional fourth week off before the cycle repeats.
  • They cause withdrawal bleeding during the break week if taken as prescribed.

Pills

  • Pills come in a 21-day estrogen and progestin combined pill, an estrogen and progestin combined pill intended for extended or continuous use, and a progestin-only “minipill.”
  • The 21-day pill pack causes withdrawal bleeding during the break week if taken as prescribed.
  • Extended or continuous cycle pills also have a week scheduled for a withdrawal bleed, but there is a longer amount of time between periods on these pills.

Vaginal rings

  • This is a 21-day estrogen and progestin vaginal ring.
  • It causes withdrawal bleeding if worn for 21 days and then removed for a week as prescribed.

Taking a 21-day pack of combined pills with a week-long break after the last active pill in your pack means that you’ll experience withdrawal bleeding before taking your next active pill.

The same goes if you reapply a birth control patch once a week for three weeks and then don’t apply it during the fourth week, or wear a vaginal ring for three weeks and remove it during the fourth week.

Much like a regular menstrual period, withdrawal bleeding is caused by a drop in hormone levels in the body. The drop in hormones triggers the release of some blood and mucus from the lining of the uterus out through the vagina.

Birth control pills come in higher and lower doses. Low-dose forms of birth control are highly recommended by doctors because they carry the lowest risk of blood clotting, heart attack, stroke, and other serious side effects. These low-dose medications usually cause lighter and shorter withdrawal bleeding than high-dose medications.

Withdrawal bleeding on a patch, ring, or combined 21-day pack of birth control isn’t the same as a regular menstrual period. It’s usually much lighter and shorter and causes fewer symptoms.

However, some women still experience menstruation-like symptoms while on hormonal birth control. These may include:

  • a mix of blood and mucus that passes through the vagina during your break week
  • abdominal bloating
  • breast tenderness
  • digestive issues, such as constipation or diarrhea&
  • fluid retention and weight gain
  • headaches
  • mood swings

While many women feel more comfortable having what feels like a “period,” it’s not medically necessary to have withdrawal bleeding each month. In fact, many women who see withdrawal bleeding as a nuisance take extended or continuous use pills with no break to avoid it altogether.

However, a major benefit is that having withdrawal bleeding may help you better keep track of your health. Having withdrawal bleeding is a sign that you’re not pregnant. Not experiencing withdrawal bleeding when you should could indicate a change in your health, including pregnancy caused by birth control failure. Keep in mind that this is rare, but it can happen.

Meanwhile, with extended or continuous-use hormonal birth control, you will never have withdrawal bleeding, and so you may not notice signs of birth control failure and early pregnancy.

When taken correctly at the same time every day (aside from your break week, if you have one), hormonal birth control is 91 to 99 percent effective at preventing pregnancy.

It may seem like you’re getting your period when you begin your break week of not taking hormonal birth control. But withdrawal bleeding isn’t the same as a regular menstrual period.

When a woman of reproductive age isn’t on birth control, the lining of her uterus thickens throughout each month. This is to prepare the body for a possible pregnancy. If she doesn’t get pregnant, she will shed this lining as blood and mucus through her vagina. This is called a menstrual period.

When a woman of reproductive age takes hormonal birth control, the lining of her uterus doesn’t thicken in the same way. The hormones in the medication prevent that from happening.

However, when the hormones are cut off during the break week, some blood and mucus will be shed through the vagina. This withdrawal bleeding is usually lighter than a natural menstrual period and lasts for fewer days.

Withdrawal bleeding happens during the last week of the course of your four-week hormonal birth control. But you may also notice some bleeding before your week of withdrawal bleeding. This is called breakthrough bleeding.

It’s common to have breakthrough bleeding when on hormonal birth control, especially within the first three months of starting a new medication.

You may also experience breakthrough bleeding if you:

  • miss one or more doses of your birth control pills
  • don’t properly apply your birth control patch
  • don’t properly insert your birth control ring
  • are taking a medication or supplement that interferes with hormonal birth control
  • continue taking your birth control during your break week

If you wear your patches or ring for all three prescribed weeks, or take all 21 active pills in the packet, you’ll still be protected from unwanted pregnancy during your break week. So it’s still safe to have sex during withdrawal bleeding, as long as you’ve taken your hormonal birth control as prescribed.

If you’ve missed any doses, use a backup method of birth control during your break week.

After stopping hormonal birth control, most women will have withdrawal bleeding within two to four weeks. After this withdrawal bleeding, your natural menstrual period should come back itself the following month. This period will be heavier and longer than withdrawal bleeding. You may also experience some premenstrual syndrome (PMS) symptoms.

It make take several months for your period to become a monthly occurrence. However, underlying medical conditions and other factors such as stress and exercise may reduce the regularity of your natural periods.

As soon as you get off hormonal birth control, you’re no longer protected from pregnancy. It’s important to switch to another form of contraception immediately if you’re not planning on getting pregnant.

If you’re trying to get pregnant, consider waiting until you’ve had at least one natural period. This can help you make sure your body is healthy for pregnancy. It will also make it easier for your doctor to establish an accurate due date when you become pregnant.

You’ll experience withdrawal bleeding during your break week if you don’t take extended or continuous-use birth control. While this bleeding isn’t the same as a natural period, it can be a helpful way to keep track of your reproductive health.

You’re still protected from pregnancy while you’re having withdrawal bleeding as long as you’ve taken your birth control as directed.

Talk to your doctor if bleeding while on birth control seems excessive or if you have other symptoms that are difficult to manage.