
When you go through IVF with a frozen embryo transfer (FET), one of the most exciting questions is: When will my baby arrive? A fet due date calculator can give you a reliable estimate of your baby’s birthday by using the exact date of your transfer and the embryo’s developmental stage.
In this guide, you’ll learn:
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How an fet due date calculator works
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How to use your FET date to predict delivery
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What happens in each month of pregnancy with growth picture
What is a fet due date calculator
A fet due date calculator is a specialized pregnancy calculator used after a frozen embryo transfer in IVF treatment. Unlike a regular due date calculator (which counts from your last menstrual period), it uses the exact transfer date and adjusts for whether your embryo was 3 or 5 days old at transfer
This gives a much more accurate estimate of your baby’s gestational age and due dat
How to use a fet due date calculator

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Enter your transfer date – the day your embryo was placed in the uterus.
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Select embryo stage – most FET embryos are 3-day or 5-day embryos.
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Calculate – the calculator adds the embryo’s age and counts 38 weeks forward from conception date (equivalent to 40 weeks from LMP in natural conception
Why fet due date calculators are more accurate
Because IVF patients know the exact day of conception (transferday, the due date is not an estimate — it’s based on precise medical timing. This is especially important for scheduling prenatal care and monitoring pregnancy milestones.
Month-by-month pregnancy pictures after FET
Here’s what you can expect visually from month 1 to month 9 after using your fet due date calculator:
Month 1 (Weeks 1–4

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Embryo implants and begins early cell division.
Month 2 (Weeks 5–8)

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Heartbeat visible by ultrasound.
Month 3 (Weeks 9–13)

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Baby’s organs form, moving into the fetal stag
Month 4 (Weeks 14–17)

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Baby begins movements felt by mom.
Month 5 (Weeks 18–21

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Gender may be revealed during anatomy scan.
Month 6 (Weeks 22–26)

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Baby’s skin is less transparent, gaining fat.
Month 7 (Weeks 27–30)

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Third trimester starts, brain development surges.
Month 8 (Weeks 31–35)

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Baby positions head-down for birth.
Month 9 (Weeks 36–40)

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Baby’s lungs mature, ready for delivery
Tips after calculating your FET due date
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Schedule all prenatal visits in advance.
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Keep track of week-by-week milestone
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Use pregnancy apps to visualize baby’s growt
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Maintain a healthy lifestyle and follow medical advice
Final thoughts on using a fet due date calculator
A fet due date calculator gives IVF parents the most accurate possible estimate of their baby’s birthday, using exact medical data from transfer day. Once you have your due date, you can enjoy following your pregnancy journey month bymonth from the first tiny embryo picture to your full-term baby bumpIf you want to understand how weeks translate into months during pregnancy, check out our full guide on how many weeks makes 9 months.
