So, you’ve been on birth control for a while, be it oral contraceptive pills (OCPs) or an intrauterine device (IUD). Everything is going well, until one day, you notice you’ve missed a period. 

Ugh, the last thing anyone on birth control wants is a pregnancy scare. After all, why else would the word “control” be baked into this popular term for contraception? 

First of all, don’t panic (I know; it's easier said than done). There are a few reasons why a missed period can occur while you’re on birth control, and pregnancy is only one of them. While OCPs and IUDs are both 99% effective (or more, in the case of IUDs) at preventing pregnancy, you can still be at risk if these contraceptives aren’t used correctly.

To better understand how missed periods can still result from using birth control, Rescripted spoke with Dorothy Bestoyong, DO, an OB/GYN based in Orlando, Florida. 

woman looking at the fine print for her birth control pill

Reasons for a missed period while on birth control

Light or no “withdrawal bleeds”

You may not have a period simply due to the type of birth control you’re using. If you’re on a traditional birth-control method (as in, estrogen-progestin birth control pills), the pills taken during the fourth week are inactive. The “period” you likely experience during this week is called “withdrawal bleeding” as your body responds to stopping the hormones. This type of birth control “can make the uterine lining thinner,” says Dr. Bestoyong, “and therefore, when [patients] have their ‘withdrawal bleed,’ it may be very light or [nonexistent].” She also points out that “sometimes people purposefully skip the placebo pills to not have a period.”

The same goes for people who have opted for IUDs: “IUDs work by thinning out the lining of the uterus,” says Dr. Bestoyong, “and so a lot of people who have IUDs may not have a period or may experience very light periods.”

Pregnancy

Yes, you can get pregnant while on birth control; if you’re sexually active and not taking your contraceptive pills consistently. “If someone is missing a majority of their OCPs, there’s a good chance their body’s ovulation is not being suppressed,” explains Dr. Bestoyong. She also mentions that pregnancy can occur if the IUD “isn’t in the optimal position.” For the record, it’s rare for an IUD to move out of place, but if you suspect that’s what’s happened (you may have menstrual cramping, discomfort during intercourse, or menstrual bleeding), see your healthcare provider immediately. 

When in doubt, take an at-home pregnancy test. But if having a child isn’t part of your life plan right now, you must keep to your OCP routine, taking your pill every day, at the same time. There’s no harm in setting a timer on your phone for those daily reminders!

Do I even need a monthly period while on birth control?

“A menstrual cycle while on OCPs or IUDs is not necessary,” says Dr. Bestoyong. Still, this is an individual decision, and worth a discussion with your healthcare provider. “If someone is taking OCPs continuously, they may want to purposefully skip periods, which is safe,” advises Dr. Bestoyong. While patients who opt for copper IUDs usually continue having a monthly period, those who go the hormonal IUD route tend to experience either lighter monthly bleeding or none at all. 

But, if you feel more comfortable with a monthly period, Dr. Bestoyong suggests taking either “the placebo pills or pills that do not have the hormones in them — or go the 4 days without any pills to experience your ‘period.’”

woman staring at her birth control pill pack

When to see your healthcare provider

“As long as you’re taking your birth control regularly, not having a period is not necessarily abnormal,” reiterates Dr. Bestoyong. But if you’ve missed your period, you’re on birth control, and you’re concerned that you might be pregnant, then it’s time to make an appointment with your physician. Once pregnancy is ruled out, you may want to use this time to discuss other birth control options.

The best way to avoid any surprises while you’re on birth control is to thoroughly research your choices before beginning a medication regimen — or having an IUD inserted. Speak with your healthcare provider about your goals and comfort levels, and they can help you decide on a birth control plan that works best for you. If you opt for contraceptive pills, talk with your doctor about which ones might cause light or no withdrawal bleeding — or whether skipping placebos is right for you. If you’re considering an IUD, remember that you may not experience any withdrawal bleeding, which can mimic missed periods.

Whatever your choice, you’re in the driver’s seat when it comes to your birth control, so ask as many questions as you need. Pills are 99% effective, but only when used correctly, so set those daily alerts! Don’t want the pressure of remembering to take a pill every day? Talk to your doctor about whether IUDs — a safe, effective, and long-term form of contraception — are right for you.


Sarene Leeds holds an M.S. in Professional Writing from NYU, and is a seasoned journalist, having written and reported on subjects ranging from TV and pop culture to health, wellness, and parenting over the course of her career. Her work has appeared in Rolling Stone, The Wall Street Journal, Vulture, SheKnows, and numerous other outlets. A staunch mental health advocate, Sarene also hosts the podcast “Emotional Abuse Is Real.” Visit her website here, or follow her on Instagram or Threads.