Plan cycle dates after IUD removal using device type, time in place, age, and whether a period has returned. See an ovulation forecast, first-period window, fertile days and a test date for the forecast.
* These dates and percentages are a planning forecast. Pregnancy is possible as soon as your IUD is removed, before the forecast dates. Use contraception if you do not want to become pregnant. Test from the first day of a missed period, or at least 21 days after the last unprotected sex if your next period date is uncertain. You do not need to wait for the forecast test date.
Methodology & Sources
What this estimates
The forecast percentages describe the timing curve shown, rather than contraceptive protection after removal. Pregnancy testing does not need to wait for the forecast date. See NHS pregnancy-test timing guidance and NHS advice on fertility after IUD removal.
The tool gives a planning forecast for ovulation and period dates after IUD removal. Fertility may be present before the forecast dates. It shows a median and middle fifty percent range, the probability that ovulation has returned by a given month, a simple fertile window, a suggested pregnancy test date, and care guidance based on whether a period has returned.
Data model
- Distribution: months to ovulation after removal is modelled with a log-normal curve.
- Baselines: hormonal IUD median 1.5 months, copper IUD median 1.0 month. Shape parameter sigma 0.40.
- Modifiers to the median (added in months):
- Years in place: +0.05 per year, cap +0.5.
- Age 35–39: +0.2. Age 40 plus: +0.5.
- BMI band: underweight +0.1, overweight +0.2, obese +0.5.
- Cycles irregular before IUD: +0.4.
- Period already returned after removal: −0.8, floor 0.5 months.
- Copper minimum floor 0.6 months.
- Probability by month X: round months since removal to the nearest month and apply the log-normal CDF.
- Date mapping: convert months to days with 30 days per month.
- First period result: if no period date is entered, use ovulation quartiles + 14 days. If a first-period date is entered, show that reported date instead.
- Fertile window: if no period date is entered, show five days centred on the median ovulation date. If a first-period date is entered, estimate ovulation 14 days before the next expected period and show the same five-day window, advancing by whole cycle lengths to the current or next window.
- Test date for the forecast: no-period estimates use earliest ovulation in the model window + 10 days. Reported-period estimates use the day after the corresponding expected period.
- Care threshold: if no period by 4 months after hormonal IUD removal or 3 months after copper removal, bring review forward by one month at age 40 plus.
Inputs and validation
- IUD type, removal date, years in place, age.
- Whether a period has returned; its date is required when Yes is selected. Cycle length has a visible 28-day default. BMI band, previous cycle pattern, and free-text reason remain optional.
- Bounds: years in place 0 to 15, age 15 to 55, cycle length 21 to 45.
Limits
This is a stylised model for education. It does not replace clinical assessment or clinic-specific guidance. Hormone withdrawal bleeding can occur without ovulation. Individual variation is common after device removal. Future removal or period dates are allowed as hypothetical planning scenarios and are identified in the result note.
Sources
- ACOG, Long-acting reversible contraception (IUDs and implants): outlines quick return to fertility after removal.
- CDC, U.S. Selected Practice Recommendations for Contraceptive Use: clinical guidance on initiation, removal, and return to fertility.
- FSRH Guideline Intrauterine Contraception: return to fertility after intrauterine methods.
- WHO, Medical eligibility criteria for contraceptive use: background on intrauterine methods and fertility after discontinuation.
What each input means
- IUD type: Choose Hormonal or Copper. Type is used to shape the return-to-ovulation curve.
- Removal date: Date the IUD was removed. Dates display in the format 01 Jan 2025.
- Years in place: Total time the IUD was in use. Used for context in the estimates.
- Reason for removal (optional): For your records and tips. Does not diagnose conditions.
- Period returned since removal? Select Yes or No. If Yes, add the date. A recent period suggests ovulation has resumed.
- Age: Used for context and care-flag thresholds.
- BMI band (optional): Additional context only.
- Cycle regularity before IUD: Regular or irregular before insertion. Helps shape windows if periods have not yet returned.
How to read the results
- Time to ovulation: Median months from removal with a 25–75th percentile band. Also shows the probability that ovulation has returned by any selected month.
- First period window: A date range for when your first natural period is expected, based on the ovulation estimate.
- TTC guidance (first 3 cycles): Brief pointers for timing intercourse in the likely fertile windows during the first three cycles.
- Test date for this forecast: A date calculated from the forecast ovulation or period window. You can test sooner according to the missed-period or 21-day guidance below the calculator.
- Care flag: A prompt such as "See a clinician if no period by X months," where X varies by IUD type and age.
- Timeline chart: A simple visual from removal to the ovulation and first-period percentiles.
If periods have not returned and the model confidence is low, the tool will show wider windows and suggest when to follow up.
Frequently asked questions
Can ovulation happen before the first natural period after IUD removal?
Yes. Pregnancy is possible as soon as an IUD is removed. The forecast dates are for planning; test timing also depends on your period and the last unprotected sex.
Does hormonal vs copper IUD change the timeline?
Type is used in the estimate. Individual return varies.
Do years in place affect return to cycles?
Years in place is one input in the planning forecast. It does not mean you remain protected from pregnancy after removal.
Can we try before the first period?
Yes. Timing intercourse in likely fertile windows may help even before the first period returns.
When should I see a clinician after removal?
Follow the care flag in your result. Seek care sooner if you have symptoms or concerns.