Nexplanon makes pregnancy very unlikely, but not absolutely impossible. In large clinical and real‑world studies, fewer than 1 person in 1,000 with the implant becomes pregnant per year when it is inserted and used correctly.

How likely is pregnancy on Nexplanon?

  • Nexplanon is reported as “over 99% effective,” meaning well under 1 pregnancy per 100 users per year.
  • Some medical sources estimate the failure rate at under 0.1% (less than 1 in 1,000 per year) when placed correctly and replaced on time.
  • In a large observational study, only a handful of pregnancies occurred among thousands of users, giving a Pearl Index (failure rate) around 0.02–0.04 pregnancies per 100 women‑years.

Put simply: if 1,000 people had Nexplanon for a year, on average 0–1 might get pregnant.

What makes it so effective?

  • It releases etonogestrel, a progestin that:
    • Stops ovulation (most cycles).
* Thickens cervical mucus so sperm struggle to get through.

* Thins the uterine lining, making implantation less likely.
  • Because it sits under the skin and works continuously, there is no daily “user error” like forgetting a pill, which helps keep the effectiveness extremely high.

When is pregnancy risk higher?

Pregnancy is still rare, but risk can go up if:

  • The implant was:
    • Inserted incorrectly or not actually in the arm (very uncommon but documented).
* Inserted at the wrong time in the cycle without backup contraception for the first 7 days, if needed.

* Left in longer than the approved duration (3 years in most guidance).
  • Certain medications are used that may reduce hormone levels, such as:
    • Some anti‑seizure medicines.
    • Certain tuberculosis or HIV drugs.
    • Some herbal products like St. John’s wort.

If any of these apply, a clinician may recommend backup contraception or a different method.

Real‑world stories vs statistics

  • On forums like Reddit, there are posts from people who say they became pregnant on Nexplanon, which can make it feel more common than it actually is.
  • Commenters and clinicians in those threads often point out:
    • Many people who never get pregnant on Nexplanon never post about it.
    • Social media algorithms tend to show dramatic or scary stories more often, which can distort perception.
  • The best overall data (clinical trials plus big follow‑up studies) still shows Nexplanon as one of the most effective contraceptives available.

When to take a test or call a doctor

Even though pregnancy is unlikely, it is important to get checked if:

  • You have:
    • New, strong pregnancy‑like symptoms (nausea, breast tenderness, unusual fatigue, or abdominal bloating).
* A sudden change in bleeding pattern that worries you, especially if your periods had stopped and then you get new symptoms.
  • You think:
    • The implant cannot be felt anymore.
    • It may be expired, or you’re close to or past the 3‑year mark.

In those situations:

  1. Take a home pregnancy test (repeat in a week if the first is negative but you still feel unsure).
  2. Contact a healthcare provider or local clinic (for example, a Planned Parenthood or similar service in your area) for an exam and, if needed, a blood test and implant check.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.