How Do I Know If My Contraceptive Implant Has Moved?

The simplest and most reliable way to check whether your contraceptive implant has moved is to feel for it. The rod sits just under the skin on the inner side of your upper arm, and you should be able to locate it by pressing gently with your fingertips. If you can feel the full length of the thin, matchstick-sized rod in roughly the same spot where it was placed, it almost certainly hasn’t moved in any meaningful way. If you can’t feel it at all, or if you notice only a partial edge where you used to feel the whole thing, that warrants a call to your healthcare provider. The story gets more nuanced from there, because “moved” can mean anything from a slight shift in nearby tissue to an extremely rare journey into a blood vessel.

How to Do the Self-Check

Your provider should have shown you how to palpate the implant right after insertion, and this is worth doing periodically. Press the fingertips of your opposite hand along the inner side of your upper arm, roughly between your elbow and armpit. You’re feeling for a firm, narrow rod about 4 centimeters long, sitting just beneath the skin surface. Run your fingers along its length. You should feel both ends clearly. Some people find it easier to locate by pinching the skin gently between thumb and forefinger.

How often should you check? There’s no official schedule, but once a month is a reasonable habit, especially during the first few months after insertion. The rod doesn’t move around day to day the way people sometimes worry it might. It’s placed in the subdermal tissue and typically stays put, with connective tissue forming around it over time. But checking regularly means you’d notice a change early if one occurred.

Warning Signs That Something Has Shifted

The most common signal is simply that you can no longer feel the implant. In one reported case, a woman noticed a tingling sensation in her armpit area, and the device had migrated toward the axilla and could no longer be detected by physical exam or even ultrasound, requiring a CT scan to locate it.¹ That’s an unusual scenario, but it illustrates the range of what “moved” can look like.

Specific things to watch for:

Loss of palpability: You could feel it before, and now you can’t, or you can only feel part of it.
New tingling or numbness: Unusual sensations in the arm, especially near the armpit or along the inner upper arm, could suggest the implant has shifted toward nerve or vascular structures.
A change in position: The rod feels like it’s in a noticeably different spot than where it was placed, or it feels deeper than it used to.
Unexplained return of periods: If your bleeding pattern changes significantly, particularly if regular periods return after having been absent, it’s worth checking that the implant is still in place.

Implants that become non-palpable should be located with imaging right away to prevent potential nerve or vascular problems down the line.² The urgency isn’t because migration is an emergency in most cases, but because knowing exactly where the device is sitting determines everything about what happens next.

How Common Is Implant Migration?

Migration is genuinely rare, but “incorrect insertion” is broader than most people realize. A large observational study tracking over 7,300 Nexplanon insertions found that roughly 13 per 1,000 insertions involved some kind of procedural issue, including cases where the implant ended up deeper than intended or wasn’t fully inserted.³ Most of those situations are caught early and managed without drama.

True migration, where the implant travels a significant distance from where it was placed, is far less common. A 2024 systematic review identified 148 independent cases of migration across the medical literature, drawn from publications spanning many years and multiple countries.⁴ Given the millions of implants placed worldwide, 148 documented cases is a very small number. The review found that about half of those migrations involved the implant reaching pulmonary blood vessels, while the rest ended up in other blood vessels or in nearby soft tissue outside the vascular system.

Those numbers need context. Case reports reflect what gets published, not everything that happens. Some cases of minor movement likely go unreported because they’re caught during routine removal and don’t cause problems. Conversely, the pulmonary cases get published precisely because they’re dramatic. The true frequency of all migration probably sits somewhere between the case-report count and the incorrect-insertion rate, but it’s clearly not something that happens to most implant users.

What Makes Migration More Likely

Research has identified several factors associated with the implant ending up deeper than expected or becoming hard to find at removal time. A retrospective analysis comparing deep removals with straightforward ones found that lower body mass index at the time of insertion, weight gain during use, and longer duration of use were all independently linked to a higher chance the implant would sit deep.⁵ Insertion by a non-specialist also showed up as a risk factor in that study, with deep removals considerably more common when the implant had been placed by someone other than an obstetrician-gynecologist.

A separate systematic review echoed these findings, listing provider training, time since insertion, higher BMI at removal, and weight gain during use as factors associated with non-palpable implants.⁶ The weight-gain finding makes intuitive sense: the implant sits in the subdermal fat layer, and if that layer changes significantly after placement, the rod can end up sitting deeper relative to the skin surface. That doesn’t mean it “traveled” necessarily, but it can make it harder to feel and harder to remove.

The most extreme form of migration, where the implant enters a blood vessel and travels through the venous system, appears to stem from the insertion itself. If the applicator needle accidentally punctures a vein during placement, the rod can enter the bloodstream rather than landing in the subcutaneous tissue.⁷ This kind of event is recognizable almost immediately because the implant won’t be palpable right after the procedure. That’s why checking for palpability at the insertion visit matters so much.

Does a Moved Implant Still Prevent Pregnancy?

This is one of the most common worries, and the answer is more reassuring than you might expect. The implant works by releasing a steady, low dose of a progestin hormone into your bloodstream. As long as the rod is somewhere in your body and the hormone is still being absorbed into your system, it’s still doing its job. A deep or non-palpable implant is not expected to affect contraceptive efficacy. The device doesn’t need to be in any specific anatomical location to suppress ovulation. It just needs to be present and releasing hormone.

That said, if the implant has been in place longer than its approved duration (currently up to five years for newer Nexplanon labeling, though earlier versions were approved for three), all bets are off regardless of location. And if you suspect the implant was never fully inserted, meaning part of the rod may have stayed outside your body or the insertion failed entirely, contraceptive protection could be compromised. The NORA study included cases of “non-insertion” in its incorrect-insertion data, which is a different problem from migration.³ If you couldn’t feel the implant immediately after placement and your provider didn’t confirm it was in place, use backup contraception and follow up.

How Providers Locate a Missing Implant

If you can’t feel your implant, your provider will start with imaging. Ultrasound is the first choice for non-palpable implants because it’s quick, widely available, and accurate for finding a rod that’s still somewhere in the arm.⁸ You can usually point to the general area where the implant was placed, which speeds things up considerably. For the current version of Nexplanon, the rod contains barium sulfate, making it visible on a plain X-ray. That radiopacity was specifically added to help locate the implant when it can’t be felt.⁹

If ultrasound and X-ray don’t find it, MRI is the next step, especially useful for implants that have migrated deep into tissue. CT scanning enters the picture when the implant may have traveled far from the insertion site. In the case of the woman whose implant migrated to her axilla, CT was what ultimately located it after ultrasound failed.¹ For the rare instances of intravascular migration, CT angiography can pinpoint the device inside a blood vessel.

One thing worth knowing: if no imaging modality can find the implant anywhere in your body, the most likely explanation isn’t that it vanished. It’s that it was never successfully inserted. A blood test measuring hormone levels can help sort this out, since an implant that is present and functioning will show measurable progestin levels.

Removal When the Implant Has Shifted

A normally positioned, palpable implant comes out through a small skin incision in a few minutes. Removal gets more involved when the implant has moved deeper or shifted from its original position. Providers with experience in these cases now often use real-time ultrasound guidance to remove deep implants through a minimally invasive approach. One study found this technique successfully retrieved about 87% of deep implants with no complications, though implants that had migrated beneath the muscle fascia were harder to reach this way.¹⁰

When a deep or migrated implant sits near important nerves or blood vessels, the stakes of removal rise. Attempts to remove implants that are deep or have migrated without proper imaging can cause nerve injury.¹¹ This is why guidelines emphasize imaging before any exploration, and why non-palpable implants should not be dug around for blindly. If a removal attempt is proving difficult, it’s better to stop and refer to a specialist than to keep probing.

Anyone who experiences numbness, tingling, or weakness in the hand or arm after an insertion or a removal attempt should be evaluated promptly. Those symptoms can indicate nerve involvement, and early referral to a nerve specialist leads to better outcomes.

The Extreme Scenario: Implants That Reach the Lungs

The most striking migration cases involve the implant entering the venous system and traveling through the heart to the pulmonary arteries. A French nationwide study identified 27 cases of pulmonary vascular migration, with the majority lodging in the pulmonary artery or one of its branches.¹² The 2024 systematic review found 74 cases of pulmonary migration in total across the published literature.⁴

These cases sound alarming, and they require surgical intervention, but most patients in the published reports were asymptomatic. The implant typically lodges in a small branch of the pulmonary artery without causing chest pain, breathing problems, or other acute symptoms. The usual tip-off is the same as any other migration: the implant can’t be felt in the arm, and imaging eventually tracks it down.

Retrieval from the pulmonary vasculature is complex. Doctors typically attempt an endovascular approach first, threading a catheter through the veins to grab the device, which avoids chest surgery. But if the implant has been in place long enough, tissue can grow around it, making catheter retrieval impossible. In one published case, encapsulation within the arterial wall led to failure of the endovascular approach, and the patient ultimately needed a video-assisted thoracoscopic surgery with removal of a small lung segment.¹³ Other surgical teams have managed lung-sparing approaches, using a mini-thoracotomy to retrieve the device without removing lung tissue.¹⁴

Whether to retrieve an asymptomatic pulmonary implant at all is a judgment call made with the patient. If you’re not planning to become pregnant and the device is still within its active lifespan, conservative monitoring may be discussed. But most patients and providers opt for removal to avoid long-term unknowns, and retrieval is necessary when someone wants to conceive and the implant hasn’t reached its biological expiration.

What to Tell Your Provider

If you’re concerned your implant may have shifted, the conversation with your provider is straightforward. You don’t need to diagnose anything yourself. The key information to share is whether you can still feel the implant, whether its position seems different, and whether you’ve noticed any new symptoms in your arm. Mention how long the implant has been in place and whether you’ve had significant weight changes since insertion, since both factors are relevant to how deep it may be sitting.

If your provider has difficulty feeling the implant during an office visit, the next step is imaging, not guessing. Providers should not attempt to remove a non-palpable implant without first confirming its location through ultrasound or another imaging modality.¹¹ If your provider seems inclined to explore without imaging, it’s reasonable to ask for a referral or to request imaging first. The inner upper arm contains nerves and blood vessels that you don’t want anyone fishing around near without a clear picture of where the implant is.

For most people reading this, the self-check will be reassuring. You’ll press your fingers along your inner arm, feel the familiar thin rod sitting right where it was placed, and go on with your day. The implant is one of the most effective and low-maintenance contraceptive methods available, and the vast majority of users never experience migration of any kind. But knowing what to check for, and knowing that a non-palpable implant deserves prompt imaging rather than a wait-and-see approach, puts you in a much better position if you’re ever in the small minority who does notice something off.