Why Am I Bleeding on the Contraceptive Pill?

Breakthrough bleeding, also commonly referred to as spotting, is unscheduled vaginal bleeding while using hormonal contraception, like the pill. It’s especially common in the first 3 months of starting the pill when your body is adjusting to the new hormone levels.

Spotting may also occur if you miss your pill or take it late because it can cause a drop in hormone levels. You are more likely to get breakthrough bleeding on the mini pill, which only contains progesterone.

Although breakthrough bleeding is often a normal and common side effect of starting or changing hormonal birth control, it can be a sign of an underlying health condition.

You should see a doctor if you:

• are bleeding for longer than 8 days in a row
• think the bleeding increases or is severe
• get pain or bleeding during or after sex
• have severe pain in your stomach or pelvis
• think you might be pregnant
• have a fever or chills
• think you may have a sexually transmitted infection (STI)
• suddenly start getting breakthrough bleeding after months of stable use
• your symptoms have not stabilised after 3 months of taking the pill properly

Just because breakthrough bleeding is a common side effect does not mean you cannot take steps to effectively deal with it:

Take your pill consistently

If you’re taking the pill, you must take it at the same time every day to keep your hormone levels consistent. Choose a time of day that is convenient for you and one that you are less likely to forget. It can help to set an alarm on your phone or use a pill tracker app.

If you are taking the mini pill, check the patient information leaflet to see if you are taking a 3-hour or 12-hour pill. Pills like Norgeston and Noriday must be taken within 3 hours of the same time each day, whereas pills like Cerazette, Cerelle, and Hana must be taken within a 12-hour window.

Quit smoking

If you smoke and you take the pill, you are more likely to experience breakthrough bleeding than non-smokers. So, quitting smoking can help manage or prevent this.

Talk to your doctor about switching pills

Talk to your doctor about switching to a different pill. They may recommend switching to a standard-dose combined pill or to a mini pill that contains a different form of progesterone.

Track your symptoms

Although tracking any symptoms, including spotting, will not prevent breakthrough bleeding, it can provide reassurance that it’s improving over time. Tracking can also help start a conversation with your doctor and enable any patterns to be identified.

Plan a withdrawal bleed

Taking a break from the hormones in certain contraceptives can help manage breakthrough bleeding. Scheduling a withdrawal bleed can reduce spotting by giving your womb a chance to shed any lining that has built up and may stop the bleeding.

Talk to your doctor about scheduling a withdrawal bleed while taking hormonal contraception.

Bleeding on the pill is common, with up to 70% of people experiencing it as a mini pill side effect in at least 1 cycle. Here are some of the most common causes of breakthrough bleeding on the pill:

You are new to birth control

You are most likely to experience spotting when you first start hormonal contraception as your body adjusts to the new levels.

Oestrogen causes your womb lining to thicken, while progesterone does the opposite. When you take hormonal birth control, you are exposed to progesterone every day, which causes your womb lining to become thin, and is one of the ways it prevents pregnancy.

So, when you first start taking the pill, your womb lining is changing, which can result in spotting. This usually improves after a few months, so it is important to give it time and be patient with your body. It should get better within 3 months.

You have missed your pill

If you miss a pill, your hormone levels can drop suddenly, causing breakthrough bleeding. That’s why it is important to take your pill at the same time every day, to keep you protected against pregnancy and to prevent side effects, such as spotting.

You are taking a low-dose oestrogen pill

If you take a low-dose oestrogen pill, like Gedarel 20/150 or Mercilon, or a progesterone-only pill like Cerelle or Norgeston, you’re more likely to get breakthrough bleeding. This is because these pills contain a high amount of progesterone, either alone or in combination with a low dose of oestrogen. This imbalance can cause your womb lining to become thinner, leading to spotting.

However, it is not usually a cause for concern or a reason to switch to a different pill or type of contraception. For most people, breakthrough bleeding goes away on its own, and your doctor will recommend waiting for 3 months to see if it settles.

You have been ill

Illness, such as being sick (vomiting) or diarrhoea, within a few hours of taking your pill could mean that there has not been enough time for the active ingredients to be absorbed, reducing your hormone levels and causing breakthrough bleeding.

If this happens, you should follow the instructions in the patient information leaflet that came with your pill. Alternatively, speak to your doctor or a pharmacist for more advice.

Drug interactions

Some medications can interfere with how well the hormones in your pill are absorbed, like those used to treat epilepsy, antibiotics like rifampicin, and herbal remedies like St John’s wort.

One study looking at the effects of the anti-epileptic drug carbamazepine found that breakthrough bleeding occurred in 80% of carbamazepine cycles compared to 20% given a placebo.

Taking the morning after pill can also cause spotting between periods because of the increase in hormones.

Breakthrough bleeding on the pill is a common, and often harmless, side effect of starting the pill or switching contraception methods. It’s usually temporary, going away after a few months, and manageable.

If you are worried about spotting, you’re finding it difficult to manage, or are getting other symptoms alongside it, you should speak to your doctor for further advice.