What Happens During an IVF Cycle? From Your First Injection to the Pregnancy Test

If you are about to begin IVF, understanding the medical steps is useful—but most patients also want to know something more practical: “What will actually happen to me during an IVF cycle?”

An IVF cycle involves much more than one procedure. Over several weeks, you may give yourself hormone injections, attend ultrasound appointments, undergo egg retrieval, wait for fertilisation updates from the embryology laboratory, have an embryo transferred or frozen, take progesterone, and finally wait for a pregnancy test.

Some parts happen at home. Others happen at the fertility clinic. And several of the most important stages happen inside the laboratory without you being there at all. A complete IVF cycle commonly takes around 3 to 6 weeks, although the exact timeline depends on the treatment protocol and whether a fresh embryo transfer takes place.

For a broader overview of IVF and its treatment options, see our main guide to IVF treatment.

What Does an IVF Cycle Include?

A typical IVF cycle can be thought of as three journeys happening together:

Before the Cycle Starts: You Receive Your Personal IVF Plan

Before starting medication, the fertility team usually reviews your previous investigations and confirms the treatment protocol. You may receive instructions covering:

• Which injections or other medicines you will take
• When each medicine should start
• How to give the injections
• When your first ultrasound is expected
• Which medications must be taken at precise times
• How to contact the clinic if you miss a dose or develop concerning symptoms

Consent documents and relevant health screening are also generally completed before treatment begins. Your IVF calendar may look very organised at this point, but it is important to understand that some dates remain provisional until your ovaries respond to treatment.

The First Part of the Cycle Depends on Your IVF Protocol

Not every IVF cycle starts in exactly the same way.

Long IVF Protocol

Some patients first take medication that temporarily suppresses their natural reproductive hormones. This phase may last approximately 2 to 3 weeks before ovarian-stimulation medication begins.

Short or Antagonist Protocol

In many modern IVF cycles, ovarian stimulation begins earlier and another medicine is introduced later to prevent premature ovulation. This avoids the several-week suppression phase used in a long protocol. Your fertility specialist selects the protocol according to factors such as age, ovarian reserve, previous response to fertility medication, and risk of excessive ovarian stimulation.

What Happens Once IVF Injections Begin?

This is when the IVF cycle often starts to feel real. You usually inject fertility medication under the skin once or more each day according to your prescribed schedule. The medicines commonly contain hormones that encourage several ovarian follicles to grow simultaneously. In an unmedicated menstrual cycle, usually one dominant follicle develops. 

During IVF, the aim is generally to develop several follicles so that multiple eggs may potentially be collected. Ovarian stimulation commonly continues for around 8 to 14 days, although your response determines the actual duration.

What Might You Feel During IVF Stimulation?

Experiences vary considerably. Some patients continue working and carrying out most normal activities with relatively little discomfort. Others notice symptoms such as:

• Abdominal fullness or bloating
• Pelvic heaviness
• Breast tenderness
• Headache
• Mild nausea
• Emotional changes
• Bruising or tenderness where injections are given

As the follicles grow, the ovaries become larger than usual, which can explain some of the fullness or pelvic discomfort experienced later in stimulation.

Why Do You Keep Going Back for Ultrasound Scans?

IVF stimulation is not simply a fixed number of injections followed automatically by egg collection. The fertility team needs to see how your ovaries are responding. During monitoring appointments, a transvaginal ultrasound is commonly used to count and measure developing follicles.

Blood hormone tests may also be performed depending on the treatment protocol and clinic. Monitoring helps answer questions such as:

• Are enough follicles developing?
• Are they growing at an appropriate rate?
• Does the medication dose need adjustment?
• Is the ovarian response unusually high?
• When should the final trigger injection be given?

What Happens If Your Ovaries Respond Differently Than Expected?

IVF plans sometimes change during stimulation. If relatively few follicles develop, the fertility specialist may discuss whether continuing the cycle remains worthwhile. If the ovaries respond very strongly, the medication or trigger strategy may be adjusted to reduce the risk of ovarian hyperstimulation syndrome (OHSS).

In some high-response cycles, eggs may still be collected but all suitable embryos are frozen instead of performing a fresh embryo transfer. This is called a freeze-all strategy. The embryo can then be transferred during a later cycle after the ovaries and hormone levels have settled.

The Trigger Injection: One of the Most Precisely Timed Parts of IVF

When the follicles have reached an appropriate stage, you are given instructions for a final maturation or trigger injection. This medicine helps the eggs complete their final maturation before retrieval. Egg collection is generally scheduled around 34 to 36 hours later.

This is one of the occasions during IVF when timing is particularly important. If your clinic tells you to take the trigger at a specific time—for example, 10:30 pm—that usually means exactly that time rather than simply “sometime that evening.” If a trigger dose is missed or taken incorrectly, contact the fertility clinic rather than trying to adjust the schedule yourself.

What Happens on Egg Retrieval Day?

Egg retrieval is usually the main procedure during a fresh IVF cycle. You are commonly asked not to eat or drink for a specified period beforehand if sedation or anaesthesia will be used. At the clinic, you are prepared for the procedure and given sedation or another form of anaesthesia according to the centre's protocol.

The fertility specialist then uses a transvaginal ultrasound probe to see the ovaries. A fine needle is guided through the vaginal wall and into the follicles. Fluid from each follicle is gently aspirated and immediately passed to the embryology laboratory. The procedure commonly takes approximately 20 to 30 minutes, although this varies.

What Is Happening in the Laboratory While Your Eggs Are Collected?

This is where the patient and laboratory sides of IVF meet. The fluid collected from the follicles is passed directly to embryologists. Under a microscope, they search that fluid for eggs.

One important point surprises many patients: The number of follicles seen on ultrasound is not necessarily the same as the number of eggs retrieved. A follicle may occasionally contain no retrievable egg, and not every retrieved egg will necessarily be mature. After collection, the embryology team evaluates the eggs and prepares them for fertilisation.

What Happens With the Sperm on Egg Retrieval Day?

If sperm from a male partner is being used, a semen sample is commonly provided around the time of egg retrieval. The laboratory prepares the sample to isolate suitable sperm. Other possibilities include:

• Previously frozen partner sperm
• Donor sperm
• Surgically retrieved sperm in selected cases

Conventional IVF or ICSI: What Happens Next?

Once eggs and sperm are ready, fertilisation occurs using one of two main methods.

Conventional IVF

Prepared sperm are placed together with suitable eggs in laboratory culture and allowed to fertilise them.

ICSI

During intracytoplasmic sperm injection (ICSI), an embryologist injects one sperm directly into each suitable mature egg. ICSI may be recommended for significant male-factor infertility, previous fertilisation problems, surgically retrieved sperm, or other specific indications. It is not automatically necessary in every IVF cycle.

The Day After Egg Retrieval: The Fertilisation Update

For many patients, this is one of the most anxiously awaited calls or messages of the cycle. The embryology team checks whether fertilisation has occurred normally. The numbers often decrease at every stage: Follicles seen → eggs retrieved → mature eggs → fertilised eggs → developing embryos → embryos suitable for transfer or freezing.

This reduction is a normal part of IVF biology. For example, collecting 10 eggs does not mean you should expect 10 embryos. Some eggs may be immature, some may not fertilise, and some embryos may stop developing during the following days.

What Happens While the Embryos Are Growing?

The embryos remain in carefully controlled laboratory incubators while embryologists monitor development. Depending on the treatment plan, embryos may be assessed through several stages. You may hear terms such as:

• Day-1 embryo: fertilisation is assessed
• Day-2 or Day-3 embryo: the embryo has undergone early cell divisions
• Day-5 or Day-6 blastocyst: the embryo has reached a more advanced developmental stage

Why Might You Not Have a Fresh Embryo Transfer?

Patients sometimes expect egg retrieval and embryo transfer to happen automatically within the same IVF cycle. That is not always the case. A fresh transfer may be postponed because:

• There is a significant risk of OHSS
• Hormone levels are not favourable for fresh transfer
• The uterine lining requires further assessment
• Embryo genetic testing is planned
• A freeze-all strategy is considered medically preferable
• No embryo suitable for transfer develops

What Happens During a Fresh Embryo Transfer?

If a fresh transfer is planned, it generally happens several days after fertilisation. Unlike egg retrieval, embryo transfer usually does not require sedation or anaesthesia. You lie on an examination table while a speculum is placed in the vagina.

A thin, soft catheter is passed through the cervix into the uterus, often with ultrasound guidance. The embryologist loads the selected embryo into the catheter, and the doctor gently releases it into the uterine cavity. The procedure normally takes only a few minutes. 

Can the Embryo Fall Out After Transfer?

No. Standing, walking, using the toilet, or travelling home does not cause the embryo simply to fall out of the uterus. Prolonged bed rest after embryo transfer has not been shown to improve IVF success. Most patients can therefore get up after the procedure and continue gentle normal daily activity unless their fertility team advises otherwise for a specific medical reason.

What Happens to Extra Embryos?

If additional embryos develop to a stage considered suitable for storage, they may be frozen using cryopreservation. These embryos may later be used for:

• Another attempt if the first transfer does not result in pregnancy
• A future sibling pregnancy
• A frozen transfer when fresh transfer was postponed

Not every embryo is suitable for freezing, and the number available varies considerably between IVF cycles.

The Waiting Period: What Is Happening After Embryo Transfer?

After embryo transfer, there is usually very little for the patient to actively do besides take prescribed medication and wait for the planned pregnancy test. If implantation occurs, the embryo attaches to the uterine lining and begins producing human chorionic gonadotropin (hCG). However, you cannot reliably tell whether implantation has occurred from symptoms.

During this waiting period, you may experience:

• Cramping
• Bloating
• Breast tenderness
• Fatigue
• Light spotting
• No symptoms at all

Having symptoms does not prove the cycle worked, and having no symptoms does not mean it failed.

Why Shouldn't You Take a Pregnancy Test Too Early?

Your fertility clinic gives you a specific date to test. Testing significantly earlier can create unnecessary confusion. A test may be negative simply because pregnancy hormone levels have not risen enough yet.

Conversely, some trigger medicines contain hCG and can remain detectable for a period after treatment, potentially contributing to an early false-positive result. Follow the date given by your fertility clinic rather than testing based on symptoms.

What Happens If the IVF Pregnancy Test Is Positive?

If your pregnancy test is positive, the clinic will usually advise you about continuing medication and arrange follow-up. An early ultrasound is generally performed several weeks later. The scan helps assess:

• Whether the pregnancy is located inside the uterus
• Pregnancy development
• Fetal heartbeat when visible at the appropriate stage
• Whether there is one pregnancy or a multiple pregnancy

What Happens If the Pregnancy Test Is Negative?

A negative pregnancy test means that particular embryo transfer did not result in an ongoing detectable pregnancy. It does not necessarily mean that the entire IVF journey is over. 

If frozen embryos remain, another embryo transfer may be possible without repeating ovarian stimulation and egg retrieval. If no embryos remain, the fertility team may review the completed cycle before discussing whether another retrieval is appropriate. The review can look at:

• Ovarian response
• Number of eggs retrieved
• Egg maturity
• Fertilisation
• Embryo development
• Transfer details

Can an IVF Cycle Stop Before Embryo Transfer?

Yes. Patients often imagine that once injections begin, an embryo transfer is guaranteed. In reality, treatment can occasionally stop at different points.

Which Symptoms During an IVF Cycle Need Attention?

Mild bloating and discomfort can occur during stimulation and after egg retrieval. However, patients should know about ovarian hyperstimulation syndrome (OHSS), an exaggerated response to fertility medicines. Contact your fertility team promptly if you develop concerning symptoms such as:

• Increasing or severe abdominal swelling or pain
• Persistent vomiting
• Difficulty breathing
• Feeling faint or significantly unwell
• Markedly reduced urine output

What Is the Most Difficult Part of an IVF Cycle?

There is no universal answer. For some patients, injections are the biggest worry before starting but become routine after several days. For others, the harder parts are:

• Waiting to see how many follicles grow
• Waiting for the number of eggs retrieved
• The fertilisation update
• Watching embryo numbers decrease during development
• Waiting for the pregnancy-test date

IVF involves repeated periods where the next result cannot be controlled by simply trying harder. Understanding that uncertainty before starting can make the cycle easier to interpret when numbers or dates change.

The Bottom Line

During an IVF cycle, treatment moves between your home, the fertility clinic, and the embryology laboratory. You begin with medication designed to develop several follicles, attend scans to monitor your response, take a precisely timed trigger injection, and undergo egg retrieval.

While you recover, embryologists identify the eggs, fertilise suitable mature eggs using conventional IVF or ICSI when appropriate, and monitor any resulting embryos as they develop. A suitable embryo may then be transferred during the same cycle, or embryos may be frozen for a later transfer.

After transfer, progesterone commonly supports the uterine lining while you wait for the pregnancy test. But IVF is not a fixed conveyor belt in which everyone reaches every stage on exactly the same day. Medication doses may change. Egg retrieval may move by a day. Embryo numbers can decrease naturally. Fresh transfer may become a freeze-all cycle. Occasionally, no embryo becomes available for transfer.

Knowing this before treatment helps you understand IVF as a monitored biological process rather than a rigid calendar—and makes each update during the cycle easier to put into context.