What’s Happening Each Week of Pregnancy? A Guide to Baby Growth & Symptoms

Finding out you’re pregnant is one of those moments that hits you right in the chest. It brings excitement, slight panic, and about a thousand questions all at once. What’s happening inside me? When will I start to show? Can I still eat biltong?

We’ve put together this week-by-week pregnancy guide for South African moms to help you follow what’s going on with your baby and your body, with tips that actually make sense for the South African medical system. Whether you’re a first-time mama or you’ve been down this road before, this is your timeline, from two pink lines to labour ward selfies.

So You’re Pregnant, Now What?

Whether you just saw those two pink lines or you’re already Googling "how big is the baby at 12 weeks?" welcome. This guide is for you.

Pregnancy isn’t just about tracking bump pics or guessing baby names. It’s a process where your baby grows, your hormones shift, and your body does some pretty mind-blowing things. But what often gets missed in global articles is how different the experience can be when you’re pregnant here, in South Africa.

From when to expect your first antenatal visit at a local clinic, to how our public vs private systems handle scans and blood tests, to understanding why your gynae may recommend certain supplements, being pregnant in South Africa is different.

So if you're wondering when to book your anatomy scan, if antenatal classes are worth it, or whether your third-trimester heartburn means your baby will have a full head of hair, you're in the right place.

The First Trimester (Weeks 1–12)

Welcome to the trimester of big changes in a very tiny package. During these first 12 weeks, your baby goes from a bundle of cells to a fully formed (but very small!) human with a heartbeat, organs, and even tiny limbs. At this stage of your pregnancy, you’re probably nauseous,  exhausted, and Googling every cramp.

This is when most early pregnancy symptoms hit. Think mood swings, tender boobs, and a serious need for naps. But it’s also when key milestones happen, like your first scan and deciding where you’ll get antenatal care.

Let’s walk through it, week by week.

What Happens to Your Baby and Your Body in the First Trimester?

• Pregnancy Weeks 1–4: 

  Technically, you're not "pregnant" yet during the first two weeks. Between weeks 3 and 4, implantation happens, and you may get your first positive pregnancy test at the end of week 4.

  
  

• Pregnancy Weeks 5–6: 

  Morning sickness often starts here. You may also have fatigue, sore boobs, and crying for no reason.

  
  

• Pregnancy Weeks 7–8: 

  Your baby’s heart starts beating, and you might see it for the first time on a scan (cue tears). Your uterus is growing, even if your jeans still fit.

  
  

• Pregnancy Weeks 9–12:

  You’re almost done with the hardest part. The scan you have around this time is super important for dating your pregnancy and checking on your baby’s development.

What to Ask Your Midwife or Doctor in the First Trimester

This is when all the big emotions and firsts happen, and naturally, your questions multiply overnight. Don’t be shy to ask:

• Should I book an early scan, or wait until 12 weeks?

• What vitamins or supplements do I actually need to take?

• Can I keep exercising, or should I take it easy?

• Is spotting in early pregnancy normal?

• Do I go to a government clinic, or can I book directly with a private midwife or gynae?

  
  

Common Concerns in the First Trimester (The First 12 Weeks of Pregnancy)

Is light bleeding normal?

A bit of spotting can happen in early pregnancy, especially around the time your period was due. But heavier bleeding or pain? Call your healthcare provider.

Can I dye my hair while pregnant?

Yes, most hair dyes are considered safe after the first trimester, especially in well-ventilated spaces. If you’re unsure, wait until after 12 weeks or ask your stylist for ammonia-free options.

What if I don’t feel pregnant yet?

Totally normal. Symptoms come and go, and some moms have barely any early signs. As long as your check-ups are on track, you’re doing just fine.

Is it safe to have sex during pregnancy?

In most cases, yes. Unless you’ve been advised otherwise for medical reasons, intimacy is perfectly safe, and sometimes even helps with nausea and bonding!

Local Tip for the First Trimester: Book your first scan with a private sonographer if your clinic has long wait times. Bonus: Some offer printed pics or videos you can WhatsApp to family.

Second Trimester (Weeks 13–27)

Ah, the “honeymoon phase” of pregnancy, when many moms start to feel more like themselves again. For most women, the nausea eases up, your energy returns (a bit), and that tiny bump starts making an appearance. You might even start to look like you have an actual baby growing, not just a food baby.

Inside, your baby is growing fast, their organs are maturing, movements begin, and that little flutter you feel soon turns into full-on kicks. It’s also the time for important checkups, like the 20-week anatomy scan, and a good moment to sign up for antenatal classes and plan your maternity leave.

Let’s break it down week by week.

What Happens to Your Baby and Your Body in the Second Trimester?

• Pregnancy Weeks 13–16: 

  Hello, energy boost! Your bump may start to show, and cravings might kick in.

  
  

• Pregnancy Weeks 17–20:

  You might feel your baby move for the first time. Many pregnant mamas describe the movement as “flutters” or “bubbles.”

  
  

• Pregnancy Weeks 21–24: 

  Your uterus is now the size of a papaya. This is a great time to join antenatal classes if you haven’t already.

  
  

• Pregnancy Weeks 25–27:

  You may experience backaches, heartburn, and stronger kicks from your baby. Keep an eye out for any new symptoms, as pregnancy problems may begin to appear if you have underlying issues.

  
  

What to Ask Your Midwife or Doctor in the Second Trimester

This is usually the most comfortable trimester, but also the one with big decisions. Here’s what’s worth discussing:

• Can I still travel now that I’m 20+ weeks pregnant?

• What should I expect at the 20-week anatomy scan?

• Is my baby moving enough? How often should I feel kicks?

• Should I sign up for antenatal classes now, and where can I do them?

• Can I still sleep on my back?

  
  

It’s also a great time to start planning your birth preferences and talk about your options, private vs public, midwife-led vs obstetric care.

Common Concerns in the Second Trimester

What if I haven’t felt the baby move yet?

First-time moms often feel movement a bit later, sometimes only after 20 weeks. If you’re past that and still unsure, check in for peace of mind.

Can I fly or go on a road trip?

Most women can travel safely up to 28 weeks, but always check with your provider. Stretch, stay hydrated, and wear compression socks if flying.

Is round ligament pain normal?

Yes, that sharp pull on one side of your belly when you move too quickly? Classic round ligament pain. Annoying, but harmless.

My gums are bleeding, should I worry?

Pregnancy hormones can make gums more sensitive. Keep brushing gently, flossing, and consider a dental visit (yes, it’s safe!).

Local Tip for the Second Trimester: You’re due for your mid-pregnancy anatomy scan (usually at 20–22 weeks). This one checks every organ and limb. Go somewhere with good image quality, it’s an important scan.

Third Trimester (Weeks 28–40+)

The finish line is in sight, but your baby’s not quite done baking. In the third trimester, things start to feel very real. Your belly is stretching, your sleep might be taking a hit, and you’re probably alternating between folding tiny onesies and wondering how on earth this baby is meant to come out.

This is the phase where your baby gains weight, settles into position, and begins to practice life outside the womb. You’ll be seeing your healthcare provider more often now, prepping your birth plan, and possibly waddling a little.

From week 28 to delivery day, here’s what to expect.

What Happens to Your Baby and Your Body in the Third Trimester?

• Pregnancy Weeks 28–32:

  Your baby's getting chubbier and stronger. Start counting kicks and preparing your hospital bag.

  
  

• Pregnancy Weeks 33–36:

  Baby settles lower into your pelvis, and Braxton Hicks (practice contractions) might begin.

  
  

• Pregnancy Weeks 37–40+:

  You’re considered full term from 37 weeks. The baby could come anytime now, or it could keep you waiting.

  
  

What to Ask Your Midwife or Doctor in the Third Trimester

The countdown is on, and now’s the time to ask all your birth-related questions. Some ideas:

• When should I call the clinic or go to the hospital?

• What are the signs of preeclampsia or other complications I should watch for?

• What happens if I go past 40 weeks?

• Can I choose to have a water birth or a natural birth in my area?

  
  

Make sure you understand your clinic or hospital’s labour policies, visiting rules, and what to pack for your stay.

Common Concerns in the Third Trimester

How do I know if it’s labour or just Braxton Hicks?

Braxton Hicks are irregular, often painless, and stop when you change position. Real contractions get stronger, longer, and closer together. When in doubt, call.

I’m not sleeping at all. Is that bad for the baby?

Baby’s fine. It’s you who needs the rest. Try naps, safe sleep aids like a pillow between the knees, and magnesium-rich snacks before bed.

Can I still have sex this late in pregnancy?

If your provider hasn’t advised against it, it’s still safe, even if you feel like a whale with swollen feet. No judgement here.

What if I go past my due date?

Totally normal. Most first-time moms go beyond 40 weeks. If you go past your due date, your provider will discuss the next steps, like monitoring or induction options.

Local Tip for the Third Trimester: Check your hospital’s labour policies. Some private hospitals in SA still have restrictions on how many support people are allowed, even post-COVID.

South African Pregnancy Must-Knows

Every pregnancy journey is unique, but where you live plays a big role in how that journey unfolds. In South Africa, your options for care, the type of supplements you need, and even what’s covered during maternity leave can look very different from what you read on global websites.

In this section, we’re going to look at the stuff that matters here at home, from which pregnancy vitamins are commonly recommended by South African healthcare providers, to how the public vs private system handles antenatal checkups, to what the law says about your rights at work.

It’s everything we wish moms knew from the very beginning.

What To Know:

• Pregnancy Vitamins: 

  Look for supplements that contain folic acid, iron, and calcium. Ask your pharmacist for SAHPRA-approved prenatal vitamins.

  
  

• Maternity Leave:

  You’re legally entitled to 4 months of unpaid maternity leave under South African law. Plan early with your employer.

  
  

• Clinic vs Private:

  Government clinics offer excellent antenatal care, but may have long queues. Private OBs and midwives provide more flexibility but come with a price tag. Choose what’s right for you.

  
  

One Week at a Time, Mama

Pregnancy can feel like the longest countdown of your life and the fastest blur all at once. But knowing what’s happening each week can make the whole experience smoother.

Whether you’re riding the wave of first-trimester nausea, shopping for maternity leggings in the second, or doing deep squats to “bring on labour” in the third, remember: you’re growing an entire human. That’s incredible!

If you ever need a check-in or just someone to say “yup, that’s normal,” we’re right here at Mums & Bums. And we’d love to walk this journey with you, week by beautiful week.

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