Early Pregnancy After IVF: hCG Blood Tests, the First Scan, and Leaving Your Clinic

Early pregnancy after IVF is the few weeks between a positive test and handover to ordinary maternity care, during which your fertility clinic usually confirms the pregnancy with hCG blood tests, keeps you on progesterone, and books an early scan at around 6 to 7 weeks. It is short, it is structured, and almost nobody prepares you for it, because every leaflet stops at the test. After our third round, the frozen transfer that became our daughter, I found that the positive did not end the waiting so much as change its shape. This is what happens next, and what each step can and cannot tell you.

The day of the positive test

A positive test is the start of a confirmation process, not a single announcement. Most clinics set the test date about two weeks after transfer and ask you to ring in with the result, whether you did a urine test at home or had blood taken at the clinic¹. What happens on that call varies: some clinics simply book your scan, while others want an hCG blood test, sometimes repeated two days later, to see that the level is rising.

The reason the test date sits where it does is set out in our guide to the two-week wait: the trigger injection given before egg collection contains hCG and can linger, so a positive taken too early may be leftover drug rather than pregnancy. By the clinic’s official date, that risk has passed and the line, faint or bold, means hCG made by an implanting embryo.

My own line was so faint that I photographed it under three different lights before believing it. The nurse on the phone told me, kindly and firmly, that a faint line on the right day is still a positive line. She was right, and it was the first of many times in those weeks that I had to take the clinic’s reading over my own.

How an IVF pregnancy is dated

An IVF pregnancy is dated as if your last period began two weeks before egg collection, so the day of collection counts as 2 weeks 0 days pregnant. That convention lets IVF dates line up with the way every midwife and sonographer counts a pregnancy. A day 5 blastocyst transfer therefore happens at 2 weeks 5 days, and a test about 9 days later falls at roughly 4 weeks pregnant.

For a frozen embryo transfer, clinics work backwards from the embryo’s age on the day it was thawed and transferred, which gives an equally precise date. That precision is one of the few genuine perks of conceiving this way: your due date is known almost to the day from the start, and the 12 week dating scan rarely moves it.

It also explains a common surprise. When the clinic says “you are about 4 weeks pregnant” on test day, that is not a mistake; it is just the counting convention, and from here on every date you are given will use it.

hCG blood tests: what the numbers mean

An hCG blood test measures the pregnancy hormone directly, and in an ongoing early pregnancy the level usually rises quickly, often roughly doubling every 2 to 3 days in the first weeks. That is why some clinics take a second sample 48 hours after the first: the trend tells them more than any single number. Others skip blood tests entirely and rely on the scan, which is an equally valid approach.

There are two things worth holding on to if you are given numbers. First, starting levels vary widely between healthy pregnancies, so comparing your figure with a stranger’s on a forum measures nothing useful. Second, a slower rise is a reason for the clinic to watch, not a verdict. The figures are interpreted alongside your dates and, a couple of weeks later, the scan. Twins can produce higher levels, but a high number alone does not confirm them; with a single embryo transferred, which is now the norm, multiple births from IVF in the UK have fallen to under one in ten².

If a level falls instead of rising, the clinic will usually describe it as a likely early loss, sometimes called a biochemical pregnancy: a pregnancy that implanted far enough to produce hCG but stopped before it could be seen on a scan. It is a real loss and it is allowed to hurt.

Progesterone and your medication

Keep taking every medication exactly as prescribed until your clinic tells you to stop, because in early IVF pregnancy the progesterone you are on may be doing work your body cannot yet do on its own. This matters most after a medicated frozen transfer, where you have not ovulated and so have no corpus luteum (the structure that normally makes progesterone) until the placenta takes over. Our guide to IVF medications and injections explains what each drug in the protocol is for.

How long to continue is a clinic decision. NICE’s fertility guideline (CG156, replaced by NG257 in 2026) advised that the evidence does not support continuing luteal phase support beyond 8 weeks of pregnancy³, and many UK clinics stop around then; others continue to 10 or 12 weeks, especially after a frozen transfer. Both are within normal practice, and the important thing is to follow the plan you are given rather than one you read online.

Alongside the clinic’s prescriptions, the standard pregnancy advice applies from the moment of the positive: 400 micrograms of folic acid a day until 12 weeks, and 10 micrograms of vitamin D daily⁴. Most people on a fertility pathway are already taking both.

The first scan at 6 to 7 weeks

The first scan, usually at around 6 to 7 weeks, is the clinic’s check that the pregnancy is in the womb and developing. It is almost always a transvaginal scan, because at this stage the pregnancy is a few millimetres long and an abdominal probe sees very little. The sonographer looks for three things: a pregnancy sac inside the womb, a yolk sac and small embryo within it, and, from about 6 weeks, the flicker of a heartbeat.

The scan also answers a question that matters for safety. An ectopic pregnancy, where the pregnancy implants outside the womb (usually in a fallopian tube), affects around 1 in 90 pregnancies in the UK⁵, and the chance is somewhat higher after IVF, particularly where there is a history of tubal damage⁶. A scan showing the sac in the womb largely rules that out. Even before the scan, symptoms such as one-sided pain, shoulder tip pain, bleeding or feeling faint need a same-day call to your clinic or an early pregnancy unit, and severe pain needs A&E.

Sometimes the answer is “come back in a week”. At 6 weeks a heartbeat may simply be too small to see, and many clinics would rather rescan 7 to 14 days later than guess. That week can feel endless, but it is a routine part of early scanning, not a hint of bad news.

I had two miscarriages before our daughter, so I walked into that first scan expecting the worst. I remember the sonographer turning the screen towards me before she said anything, which I have since learned is a deliberate kindness, and the tiny flashing pulse in the corner of a grey shape. I cried, and so did my partner, and then I asked her to check again.

Leaving the fertility clinic

Most fertility clinics discharge you to routine maternity care once a scan has shown an ongoing pregnancy in the womb, usually somewhere between 7 and 12 weeks. Some do one scan and discharge; others offer a second at around 8 or 9 weeks first. You then contact your GP or local midwifery service to book in. The NHS puts the first midwife (booking) appointment at 8 to 12 weeks, and the dating scan follows between 11 and 14 weeks⁷.

Leaving the clinic is a strange moment. For months or years, a team has watched every follicle and blood result, and suddenly you are one name on a busy antenatal list with a gap of weeks before anyone looks at you again. Tell your midwife at booking that you conceived through IVF and mention any relevant history, such as previous losses, so they can decide whether you need any extra care. Your clinic will also usually ask you to let them know the outcome of the pregnancy later on, because UK clinics report results to the regulator, which is where the IVF success rates you compared at the start come from.

If you have had previous miscarriages, it is reasonable to ask your GP or midwife whether a reassurance scan through an early pregnancy service is available before the 12 week scan; some areas offer one, and some do not.

The anxiety nobody mentions

Feeling anxious rather than joyful after a hard-won positive is common and normal. After a long road, a pregnancy can feel provisional for weeks, and many people describe holding their breath until the 12 week scan or well beyond. The stress of infertility has been compared to that of a serious illness, and it does not switch off because a test changed colour.

It can also be isolating in a particular way. Friends who are still trying may be the people who understood you best, and telling them can feel like leaving them behind; at the same time, a fertility community does not always feel like your place any more. Fertility Network UK runs support for people in exactly this in-between position⁸, and many clinics offer a counselling session after a positive as well as after a failed cycle.

What helped me was setting small horizons: get to the scan, then to discharge, then to booking, then to 12 weeks. I did not try to feel excited on schedule. I let the milestones do the reassuring and saved the excitement for when it arrived on its own, which it eventually did.

This is general information and not medical advice about your pregnancy. Clinics differ in how they confirm, scan and discharge, and your own fertility team, midwife or GP are the right people to ask about your dates, your medication and anything that worries you.