After 5 Days of IVF Injections: What Happens

After 5 Days of IVF Injections, you may feel a little bloated and heavy, or you may feel completely normal. Either way, a quiet worry may have crept in: Is this actually working?

It’s one of the hardest stretches of IVF, precisely because the most important thing happening to your body right now is happening where you can’t see it. There’s no daily proof, no obvious sign. Just injections, and waiting, and wondering. So let’s pull back the curtain. Here’s exactly what your ovaries are doing after five days of injections, what that first scan around now is looking for, and why what you feel, or don’t feel, isn’t the measure of whether it’s working.

A Quick Recap: Why You’re Injecting After 5 Days of IVF Injections

In a natural month, your ovaries grow a whole batch of small follicles but allow only one to mature and release an egg. The rest fade away. For IVF, one egg isn’t enough; the more mature eggs collected, the more chances to create healthy embryos. That’s the entire job of your daily injections. The hormone in them, FSH, essentially tells your ovaries: this month, don’t pick just one; grow the whole group.

So from the first injection, your body is being gently redirected to do something it normally wouldn’t: bring several follicles along together.

What’s happening in your ovaries by day 5

By the time you’ve done about five days of injections, that redirection is well underway. Inside each ovary, a cohort of follicles the tiny fluid-filled sacs that each hold an egg is growing in parallel rather than one pulling ahead. At this stage they’re still small, usually somewhere around 6 to 12 mm, but they’re on the move, adding roughly 1 to 2 mm a day.

As those follicles grow, they release estrogen (estradiol), so your hormone levels are climbing steadily in the background. That rising estrogen is quietly doing a second job too: thickening the lining of your womb, preparing it for a possible embryo later. And because you now have multiple growing follicles instead of one, your ovaries themselves are becoming larger and heavier than usual, which is the source of that bloated, full feeling many people notice around now.

None of this is visible to you. But on an ultrasound screen, it’s unmistakable, which is exactly why day 5 is when your doctor takes the first proper look.

Day 5 is your first big checkpoint

Somewhere around day 5 or 6 of stimulation, you’ll have your first monitoring visit, and it’s an important one. It usually involves two things done together: a transvaginal ultrasound and a blood test.

The ultrasound counts how many follicles are developing and measures their size, and checks how your uterine lining is thickening. The blood test measures your estradiol level, which should be rising in step with the follicles you can see on screen. Together, these two give your specialist the first real answer to the question you’ve been asking all week: how are your ovaries responding?

What your doctor is deciding

This checkpoint is not just observation; it’s where your treatment gets fine-tuned to your body. Based on what the scan and bloodwork show, your specialist may make a few decisions.

They may adjust your dose, nudging it up if your follicles are growing more slowly than hoped, or easing it down if your ovaries are responding very strongly. And around this point, many patients are asked to start an antagonist injection (you may hear names like Cetrotide, Ganirelix, or Orgalutran). This is a small daily injection added alongside your stimulation, and its job is simple but important: it stops your body from releasing the eggs too early. Without it, a natural hormone surge could trigger ovulation before the eggs are ready to be collected, so the antagonist quietly holds that surge back until the timing is right.

If this is added to your routine now, it isn’t a sign anything is wrong. It’s a planned, protective part of the protocol.

What you might feel, and what’s normal

Here’s the reassurance worth holding onto: how you feel is not a reliable gauge of whether stimulation is working. The real evidence lives on the scan and in your bloodwork, not in your symptoms.

That said, some sensations are very common by day 5. As your ovaries enlarge, mild bloating, a feeling of fullness or heaviness in the pelvis, and some tenderness are all normal. Hormones can bring mood swings, tiredness, or breast tenderness. Injection sites may bruise a little. All of this is your body doing exactly what’s being asked of it.

And if you feel almost nothing? That’s equally normal. Plenty of people sail through stimulation with barely a symptom and go on to have an excellent response. Feeling little does not mean the injections aren’t working.

The one thing to stay alert to is the rare warning sign of your ovaries over-responding: rapidly worsening bloating with significant abdominal pain, quick weight gain, reduced urination, or breathlessness. These can point to ovarian hyperstimulation, and if you notice them, you should contact your clinic promptly. They’re uncommon, and catching them early is exactly why you’re being monitored so closely.

The road from day 5 to egg retrieval

Day 5 is roughly the midpoint of a stimulation phase that usually runs about 10 to 14 days in total. From here, the path is fairly predictable.

Stage	Roughly when	What’s happening
First scan	~Day 5–6	Follicles ~6–12 mm; dose fine-tuned; antagonist often started
Mid-stimulation	~Day 8–9	Leading follicles reach ~12–16 mm; more scans every 1–3 days
Nearly ready	~Day 10–12	Several follicles reach ~17–20 mm and are judged mature
Trigger shot	When follicles are mature	A final injection matures the eggs for collection
Egg retrieval (OPU)	~34–36 hours after trigger	Eggs are collected under sedation

So after this first checkpoint, you’ll simply keep injecting and keep being scanned every couple of days, watching those follicles climb toward the finish line. Once enough of them reach maturity, you’ll get your trigger shot, and egg retrieval follows about a day and a half later.

If your response isn’t “textbook”

Very few cycles unfold exactly like a chart, and a response that surprises your doctor is not a failure; it’s information they act on.

If your follicles are growing slowly or fewer are developing than expected, your specialist may raise your dose and give your ovaries a little more time. Some ovaries are simply steadier responders, and a longer, gentler climb can still end well. If, on the other hand, you’re a strong responder with many follicles as is common with PCOS the focus shifts to keeping you safe: easing the dose, using the antagonist, and sometimes planning to freeze all the embryos and transfer them in a later, calmer cycle to avoid ovarian hyperstimulation.

Both scenarios are routine. The entire reason for these frequent scans and blood tests is so your plan can bend to fit your body in real time, which is precisely what good stimulation looks like.

The Imprimis IVF approach

At Imprimis IVF, no two stimulation cycles are run from the same fixed script. Your dose, your protocol, and the timing of every decision are shaped around how your ovaries respond, checked through careful day-by-day monitoring with in-house imaging and lab support. High responders are watched closely to prevent OHSS; slower responders are given the time and adjustment they need. And at every visit, what the scan shows is explained to you in plain language because getting through this invisible, anxious phase is far easier when you actually understand what your body is doing.

If you’re in the middle of stimulation right now and something feels unclear or worrying, that’s exactly what your care team is there for a quick call or your next scan can turn uncertainty back into reassurance.