Why am I spotting on birth control? 8 possible reasons why

Dealing with any kind of vaginal bleeding can be a bit unnerving, even if it’s very light. At least when it comes to your period, you may know roughly when it’s due. But bleeding between periods (also known as spotting or breakthrough bleeding) can catch you off guard. 

Spotting is a common side effect of hormonal birth control. As annoying as it can be, the good news is that it usually doesn’t signal that anything is wrong with your health or the contraception you’re taking. There are also things you can do to improve it. Keep reading to find out the possible causes of spotting on birth control and what you can do about it. 

Key takeaways

• Spotting is a common side effect of any type of hormonal birth control.
• In general, breakthrough bleeding on birth control improves over time.    
• In the meantime, there are things you can do to help decrease it, such as quitting smoking and taking your pill at the same time each day.

Why am I spotting while on birth control?

It’s a common side effect of hormonal birth control

“Spotting is a common side effect of hormonal birth control, mainly because these types of contraceptives cause the lining of the uterus to temporarily become thinner,” says Dr. Jennifer Boyle, obstetrician and gynecologist, Massachusetts General Hospital, Massachusetts, US. “As the lining changes to become thinner and more inactive, it is very common to have spotting.” 

You may notice breakthrough bleeding with any kind of hormonal contraception, including: 

• Pills
• Implants
• Shots
• Hormonal intrauterine devices
• Skin patches
• Vaginal rings

So what is it about hormonal birth control compared to nonhormonal birth control that causes the uterus to bleed? You guessed it: hormones. “Hormonal birth control contains either estrogen and progestin (a synthetic form of the natural hormone progesterone that the ovary releases after ovulation) or progestin only,” says Dr. Boyle. “Estrogen causes the lining of the uterus to grow and thicken, whereas progesterone causes it to stabilize.” 

Hormonal birth control changes the hormone levels in your body. “In a natural cycle, your body is only exposed to progesterone during the last two weeks of your cycle, after you ovulate,” says Dr. Boyle. “With hormonal birth control, you get the progesterone effect every day. This causes the uterine lining to become thin and inactive. It is not growing and developing like it would be in a natural cycle.”

You’re taking a progestin-only type of hormonal birth control

Because it’s the imbalance of progesterone that causes the uterus lining to become thinner, spotting is more common with progestin-only pills than with combined pills, Dr. Boyle explains. In one study, 70% of people taking the progestin-only pill experienced spotting in one or more cycles. “With progestin-only pills, you are only getting progesterone and not estrogen,” says Dr. Boyle. “This can make the uterine lining very thin and more likely to spot. But this is temporary and not in a way that will cause any problem with pregnancy in the future.”

Another type of birth control pill that has a very low dose of estrogen is also more likely to cause spotting for the same reason. “The balance of more progesterone/less estrogen makes the lining more fragile and can spot more easily,” says Dr. Boyle. 

Sometimes, women and people with periods are unable to take extra estrogen. For example, if you have recently given birth, are breastfeeding, or have a history of blood clots or heart problems, your doctor may suggest you try progestin-only pills (sometimes called the mini pill). 

“This type of spotting usually doesn’t cause any medical problems (such as anemia), so if you need to be on a progestin-only or low-dose estrogen pill for medical reasons or for personal preference, then you should continue with that method,” says Dr. Boyle. “The spotting is not usually a reason why you need to change and often goes away on its own.”

You’ve recently tried a new type of hormonal birth control

You’re most likely to experience breakthrough bleeding when you first start hormonal birth control as your body is adjusting to the new hormone levels. “In the beginning, the uterine lining is thinning out and changing,” says Dr. Boyle. “After two to three months of using a method, the lining will have become thinner and more stable, causing most unscheduled bleeding to improve.”

These changes aren’t permanent, though. “Don’t worry, this is not a forever change,” adds Dr. Boyle. “Quickly after stopping hormonal contraception, especially birth control pills, patch, or ring, the uterine lining will grow and develop normally again as your cycle returns.” 

You take your pill continuously

Most birth control pills are designed to include a break, where you temporarily stop taking an active pill and have what’s called a withdrawal bleed. “Remember that when using hormonal birth control, you don’t have a real period,” says Dr. Boyle. “If you have scheduled bleeding with your method, it is a withdrawal bleed that happens when you pause taking the medication.”

Sometimes delaying a withdrawal bleed — or avoiding it completely — can make life a lot easier. Maybe you’re going on vacation and want to run two pill packets together, or perhaps you experience difficult symptoms of premenstrual syndrome or your period and want to continue your pill without any breaks at all. Taking your pill continuously won’t harm your health, but the downside is you are more likely to get spotting. 

Dr. Boyle explains, “When people take their pills continuously, the uterus lining can become so fragile that it spots. This is not dangerous now or for the future. But to get the spotting to go away, people often need to pause the pills for three to seven days. This will allow the lining to shed and then regrow and become less fragile.” 

You may feel like a little spotting is worth it if it means no withdrawal bleeds. It’s a personal choice and all comes down to what feels right for you. 

You missed a pill

If you’ve forgotten to take a pill on time, try not to give yourself a hard time about it. We’ve all been there. But if this has happened lately, it could be the cause of any breakthrough bleeding you’re getting. “Missing one or more pills can trigger spotting,” says Dr. Boyle. “When you miss pills, the level of estrogen and progestin, or just progestin in the case of progestin-only pills, decreases, and this can trigger a withdrawal bleed that is often spotting.”

It’s worth flagging that the progestin-only pill needs to be taken within three hours of the same time each day to be effective, compared to 12 hours for the combined pill. This is why taking the mini pill at the exact same time every day will minimize your chances of getting any spotting. And remember, if you’ve missed an active pill, you’ll need to use extra protection, such as condoms, for seven days if you’re taking the combined pill, and for two days if you’re on the mini pill. 

You took the morning-after pill 

The emergency contraceptive pill (ECP or sometimes called the morning-after pill) can be clutch when you’re trying to avoid pregnancy. But while it’s not a cause for concern, it can sometimes cause spotting between periods. This is because like the birth control pill, ECPs change the balance of hormones in your body. Here, the bleeding or spotting is caused by an increase in hormones, rather than a decrease that can lead to withdrawal bleeding.  

It can also cause changes to your normal menstrual cycle, but if your period is late after taking emergency contraception, reach out to your health care provider or consider taking an at-home pregnancy test just in case. 

You may have a benign growth

Spotting can also be a sign of having noncancerous or benign growths in your uterus, like fibroids or polyps. These are pretty common (70% of women are estimated to have at least one fibroid by age 50) and usually nothing to worry about. 

“If you are worried about spotting on contraception, and you have already made sure that you are taking your pill at the same time every day, then you should call your doctor or gynecologist, and schedule a check-up,” says Dr. Boyle. “They can look at the vagina and cervix to make sure there are no benign growths, such as polyps, that could be causing the spotting.”

If you think you might have benign growths like fibroids or polyps, know that they can be treated. So try not to worry and schedule an appointment with your doctor so they can look into it.  

There’s a chance you have an STI 

Sexually transmitted infections (STIs) like chlamydia and gonorrhea can cause unexpected spotting. If you think this could be the reason behind your spotting, then it’s important to get tested as soon as possible. Chlamydia and gonorrhea are the most common STIs in the United States, which is why it’s recommended that you get tested for them once a year if you’re either: 

• A woman under 25
• A woman over 25 with new or multiple sex partners

It’s natural to feel anxious if you think you could have chlamydia or gonorrhea, but know that both can be easily treated with antibiotics. STIs are also nothing to be ashamed of and more common than you might think, affecting 1 in 5 people in the United States at any given time. 

“Hormonal birth control doesn’t prevent sexually transmitted infections, so if the spotting is new, it’s good to get screened for infections,” says Dr. Boyle. “Treating an STI will often make the spotting go away.”

Can you be pregnant and have a light period on birth control?

Light bleeding or spotting can be an early pregnancy symptom, known as implantation bleeding. “This can happen when the fertilized egg burrows, or implants, into the uterine lining,” Dr. Boyle explains. “So in that way, yes, there can be light bleeding if someone on birth control becomes pregnant.” 

However, the chances of getting pregnant if you’re using your birth control correctly are low. Birth control pills are 99.7% effective with perfect use and 93% effective with typical use. So spotting by itself isn’t a surefire sign of pregnancy. “We don’t consider spotting on birth control pills to be a sign that someone is pregnant,” says Dr. Boyle. “If you have other reasons to think you could be pregnant, definitely take a test.” 

How long does spotting on the pill last?

If you’ve recently started taking the pill and are getting spotting, hang in there. “We usually counsel people that, in most cases, unscheduled spotting will resolve after two to three months of taking birth control pills,” says Dr. Boyle. If the spotting has lasted for longer than this, or if you’re worried, speak to your doctor, who’ll be able to advise and support you. 

How to stop spotting

While spotting is a normal side effect of hormonal contraception and usually goes away after a few months, there are some things you can do that may help to stop it.

Quit smoking

If you currently smoke, quitting might help to stop any spotting. Women who smoke are more likely to experience breakthrough bleeding on hormonal birth control than those who don’t. 

Take the pill at the same time every day

If you’re taking birth control pills, it can help to take the pill at exactly the same time every day. Doing this may not just help to reduce spotting, but will make your birth control as effective as possible. 

Plan a withdrawal bleed 

Because taking continuous hormones — whether that’s through the pill or another form of hormonal birth control, like the vaginal ring — can trigger breakthrough bleeding, having a break can help. In some cases, scheduling a withdrawal bleed for every few months can give the uterus a chance to shed any built-up lining, reducing spotting. However, it’s best to discuss this with your health care provider. 

Track your spotting

Tracking your breakthrough bleeding won’t help it go away, but it can provide you with reassurance and encouragement that it’s decreasing over time. You can do this with a period-tracking app like Flo. We’ll even create a helpful cycle report so you can spot patterns.

Remember that while these tips can help, it’s important to reach out to your doctor if you’re ever worried about breakthrough bleeding on birth control. “If the spotting is bothering you, and it continues even with great pill-taking habits, then talk to your doctor and see if there’s a different method that might have less spotting,” says Dr. Boyle. “Sometimes switching brands of pills or switching to a pill with a higher estrogen level can help with spotting.” 

She continues, “However, I tend to see that if it helps, it usually just does so temporarily, and then the spotting comes back. I generally tell people that if they are overall happy with their birth control, then it may be better to continue with it than try to get the spotting to go away, especially since it is not dangerous.”