Your pregnancy: 5 weeks pregnant

Last modified on Thursday 12 May 2022

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Although your baby's only the size of a cake sprinkle, it's never too soon to watch what you eat and start taking your pregnancy supplements. Here's some food for thought now that you're five weeks pregnant.

What’s happening at 5 weeks?

Here are the key things you can expect from your pregnancy at this stage:

  • Your baby has a growth spurt.
  • Your plug forms (see What's going on with your body? below).
  • Pregnancy hormones really start to kick in.
  • Time to watch what you eat.

How big is your baby?

This is an exciting time in your baby's development! The embryo may be tiny, but it's just started on the first of many growth spurts and will double in length this week – from 2mm to 4mm.

At the moment, your baby is made up of three layers – the ectoderm, the mesoderm, and the endoderm. These will eventually form all the organs and tissues.


Your little one looks more tadpole than baby at the moment, with what looks like a longish tail and tiny eye sockets appearing like grooves either side of their developing brain.

Development of the heart, kidneys and liver are also underway. In fact, it's around now that your baby's tiny heart begins to divide from a single tube into four separate chambers, beating and pumping blood.

Sizewise, your baby's no bigger than a cake sprinkle.

Cake sprinkles in a bottle
Your baby will be the size of a cake sprinkle when you're five weeks pregnant.

What's going on with your body?

One minute you’re buzzing with excitement, the next you’re sobbing over the latest John Lewis advert. Welcome to pregnancy hormones!

It's totally normal to feel a bit all over the place right now. Not only are your hormones going mad, but you're also facing a major life change. Plus, at this early stage, you might not have told people yet, and it can be a struggle to keep all those early symptoms to yourself.

Be as kind to yourself as you can. If you need a bit of extra rest because pregnancy fatigue is kicking in, do take naps when you can. Practise self-care – just 10 minutes of slow breathing a day can help you to focus and manage your moods.

Find ways to treat yourself, too. A warm bath, a gentle walk, a manicure, your favourite book or box set – whatever makes you feel good.

The good news is that this rollercoaster of emotions is unlikely to last throughout your pregnancy. Most women feel better in the second trimester (from 13 weeks), as their body adjusts to the pregnancy hormones. So just hang in there a little longer!

The mucus from your cervix will now be thickening to form a plug that helps prevents infections from reaching your baby. The sight of this 'plug' in your knickers at the end of your pregnancy is one of the signs that labour could soon be starting.

What to expect this week: diet advice

Before pregnancy cravings kick in, it’s a good idea to give your daily diet a once-over.

There are certain foods you should now avoid, and others that you should be wolfing down. And, sorry to be the ones to break the news, but pregnancy does not mean eating for two (in fact, the latest research suggests you don't need to eat any more than usual until the third trimester, and even then it's only 200 extra calories per day).

Some of the key things to avoid include:

  • Alcohol – it’s now recommended that you avoid drinking alcohol altogether if you’re pregnant.
  • Unpasteurised, mould-ripened or soft blue cheese – when in doubt stick to hard cheese like Cheddar (though hard blue cheese like Stilton is OK).
  • Caffeine – drinking more than 200mg a day (about two cups of instant coffee) has been associated with miscarriage and low birth weight. Remember that tea, cola and chocolate also contain caffeine, as well as coffee.
  • Unwashed or uncooked foods – hygiene is your friend during your pregnancy so make sure fish and meat are cooked through until piping hot in the middle and always wash fruit, veg and salad.
  • Liver and liver products – these contain high levels of vitamin A, which aren't safe for your developing baby.
  • Oily fish – don't eat more than two portions per week.

See our definitive list of all the foods to avoid in pregnancy.

It's also crucial to take certain supplements during your pregnancy.

The Department of Health recommends that all pregnant women take: 

  • 400 micrograms (mcg) of folic acid each day – you should ideally take this from before you are pregnant until you are 12 weeks pregnant as it reduces your baby's risk of developing neural tube birth defects such as spina bifida. If you haven't started yet, don't panic, but start taking it as soon as possible.
  • 10 micrograms (10mcg) of vitamin D a day.

If the iron level in your blood becomes low, your GP or midwife will advise you to take iron supplements.

What to do this week: avoid germs

We’re not talking biohazard suits and breathing apparatus here, but there are infections that can be dangerous to your baby, so basic hygiene habits are important.

Be sure to wash your hands with warm water and soap before handling food, before eating and after using the loo. Also give them a wash if you've been on public transport or handled money.

If you have a cat, be aware that their poo may contain toxoplasma, an organism that causes toxoplasmosis infection which can damage your baby. Give the job of litter-tray emptying to your other half, or make sure you wear gloves.

Similarly, wear gloves when you’re gardening in case the soil has been cat-pooed (even if you don’t have a cat – as next door’s is likely to be using your garden as a toilet).

There's no need to go overboard by sanitising everything in your home, but it's always a good idea to be a bit more mindful of cleanliness and hygiene when you're pregnant.

Your 5 week to-do list

1 Just found out you're pregnant? Book a GP appointment.

2 Check that any medication you take is safe to take during pregnancy. Don't stop taking it without checking with your GP first though.

3 Join your due date club in the Netmums forum, to meet other mums-to-be who are due at the same time as you and share your pregnancy experience

4 Check that your job is safe to be doing – if you're working with chemicals or radiation, you may need to talk in confidence to your employer or HR manager.

5 Make sure you know what you should and shouldn't be eating, and which supplements you should take (see above). Find all the guidelines on what's safe to eat in pregnancy here.

What to watch this week...

Get expert tips on what to expect at 5 weeks pregnant from our midwife.

What happens next week...

Want to know what happens when you're six weeks pregnant? Or maybe you've already forgotten what you read last week? Just click on the numbers above to find out more about what to expect when you're that number of weeks pregnant.

Just found out you're pregnant? Work out your due date with our handy due date calculator below ...

Due date calculator

Select the first day of your last menstrual period and the average length of your menstrual cycle

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