Congratulations if you’ve just found out you’re pregnant! We've compiled this pregnancy week by week article because we know you're probably dying to know what happens next!
Each week in your first trimester brings new and exciting developments – your baby is only tiny, but this stage lays important foundations for the rest of his or her life!
Do you want to know what your baby is doing in there, when you will feel their first movements or how long morning sickness can last?
Find out what will happen in your pregnancy week by week.
You might like to see our dedicated pregnancy week by week section, which has each week detailed individually with an illustration of development.
Pregnancy Week By Week
So, let's go! Here's what you need to know about pregnancy week by week in the first trimester:
Pregnancy Week By Week: Week 1
You aren’t actually pregnant yet – in fact your period has just started! Even though you have conceived your baby, gestation is counted from the first day of your last menstrual period. This is so your estimated due date can be worked out as approximately 40 weeks from today.
Even early in pregnancy there is no exact science to working out when your baby will be born – only 3-5% of babies are actually born on their due date! It can be a lot easier to tell excited family and friends a due month or even a due season!
At the moment, your baby is still a small, single celled egg (ovum) hiding in one of your ovaries.
The diet of both mother and father before conception can not only impact fertility and the pregnancy (for example, likelihood of gestational diabetes), but the future health of the baby too. It’s a good idea for both of you to clean up your diet and make good lifestyle choices over the next few weeks, to increase the chances of conception and a healthy pregnancy and baby. Eating whole foods (protein, good fats, fruit, veggies, nuts, seeds, greens) and cutting out processed foods (grains, sugars) is ideal.
Women are usually advised to start taking folic acid supplements when trying to conceive or newly pregnant – but before you do, read this important article.
Read more about the first week of pregnancy.
Pregnancy Week By Week: Week 2
Once your period finishes, the lining of your uterus (endometrium) will thicken in preparation for implantation of a fertilised egg. This thickening is caused primarily by an increase in the hormone progesterone. If implantation doesn’t happen, progesterone levels fall and your body gets rid of this thickened layer, which is your menstrual period.
An egg follicle on one of your ovaries gets ready to release an egg. This is known as the follicular phase. Usually only one egg is released, although sometimes 2 or more eggs are released and are responsible for the birth of fraternal twins.
Unlike a man who produces new sperm through his life, a woman is born with a lifetime’s supply of eggs already in her ovaries.
Read more about the second week of pregnancy.
Pregnancy Week By Week: Week 3
This is it — the magic week when you conceive!
It takes about 10 hours for your partner’s sperm to reach your egg.
Fertilisation usually occurs in the fallopian tubes as the egg is swept down toward the uterus. As soon as the egg is penetrated, it starts to rapidly divide. It takes about 6 days to journey to the uterus and once there, will attach itself to the uterine wall (implantation).
Read more about week 3 of pregnancy.
Pregnancy Week By Week: Week 4
Your period may be due and not arrive – you may suspect you are pregnant.
Some women do experience implantation bleeding when the fertilized egg burros into the uterine wall. You may begin experiencing some early signs of pregnancy. If you do think you are pregnant, you are probably curious when you are due – our due date calculator will give you an estimated date.
The next six weeks are a critical stage of development for your baby so it’s important to address any health and lifestyle issues early on. Consider a prenatal multivitamin and up your dietary intake of folate rich foods to help your baby’s neural tube develop properly and avoid spina bifida. Find out more here.
Read more about week 4 of pregnancy.
Pregnancy Week By Week: Week 5
If you have confirmed your pregnancy by a home pregnancy test, you know you are definitely pregnant.
But your body could already be giving that away – your breasts and nipple may feel very tender. You might have also felt some cramping and backache. If this is very painful, see your care provider.
Your baby is very tiny and looks a little bit like a tadpole. The placenta and umbilical cord have developed and are helping to nourish your baby as they will for the next 8 months.
Read more about week 5 of pregnancy.
Pregnancy Week By Week: Week 6
Pregnancy tiredness may have suddenly kicked in this week!You are making a baby after all, it’s ok to be more tired than normal.
You will have noticed you need to pee more often, especially in the middle of the night.
You may also be feeling a bit queasy already. Morning sickness affects most women and usually passes after the first trimester. Some unlucky women develop hyperemesis gravidarum, which is a severe form of morning sickness. No one is sure what causes morning sickness but it is suspected that the rising levels of HCG play a major part.
Your baby starts to look a little like a ‘jelly bean’ and has a bloodstream, and a heart which has started to beat and pump. Four little buds have formed which will become arms and legs soon.
Read more about week 6 of pregnancy.
Pregnancy Week By Week: Week 7
Not much has changed from last week except your morning sickness could be getting worse. Try to eat something dry like crackers first thing in the morning before you get out of bed. Keep eating small, frequent meals or snacks to avoid going too long without food. Some women swear by ginger in any form, others swear by acupressure bracelets. It might take you a while to find out what works best for you.
Your baby is now the size of a cherry, with arms and legs! Baby’s face is beginning to form, as well the teeth and tongue.
Read more about week 7 of pregnancy.
Pregnancy Week By Week: Week 8
You might have noticed a tiny bump appearing around your middle. Your clothes might be feeling a bit snug and uncomfortable.
Hormonal changes may be affecting your skin and you might see some pimples. Your blood volume is starting to increase and this can put pressure on the blood vessels in your nose and gums, increasing bleeding.
Your baby’s face has formed and the heart is beating regularly. Organs are beginning to form, as well as muscles and nerves. Baby’s skin is very thin and the brain and veins are still visible.
Read more about week 8 of pregnancy.
Pregnancy Week By Week: Week 9
Around this stage of pregnancy you might have noticed your bra is feeling uncomfortable. This is because your breasts are beginning to change in preparation for lactation after birth. It’s a good time to purchase some maternity bras that will see you through pregnancy.
While you can’t see what’s happening, your baby is developing very quickly now and looks like a person. You can’t feel it yet but your baby has started to move and flex arms and legs, as elbows and ankles have developed. The placenta has taken over nourishing your baby and is now completely developed.
Read more about week 9 of pregnancy.
Pregnancy Week By Week: Week 10
Are you feeling a little crazy and emotional? It’s pretty normal around this stage of pregnancy to experience some wild mood swings, thanks to pregnancy hormones. Try to get enough rest and ask for your partner’s support and empathy.
Baby has been adding some finishing touches – hair and fingernails have started to grow. Eye colour has been decided and the nervous system is beginning to develop. Large muscles are also forming and your baby’s head has grown.
Read more about week 10 of pregnancy.
Pregnancy Week By Week: Week 11
Some pregnancy symptoms like morning sickness and tiredness may be easing by now. You could be feeling more energetic and this is a great time for you and your partner to start enjoying the idea of sharing your news (if you haven’t already!). You might be finding it hard to ‘hide’ your belly now.
Your diet should focus on fresh, wholefoods to help support your body as you nourish your growing baby. If you have any concerns about your health, make an appointment to see your care provider.
All of baby’s major organs are formed and starting to function. Movements are increasing and baby is able to suck and swallow. The placenta is supplying all nourishment and taking away waste.
Read more about week 11 of pregnancy.
Pregnancy Week By Week: Week 12
Around this time you may have decided to have an ultrasound to check on baby’s growth and development.
Your uterus is now above your pelvis and you may notice you don’t need to wee so often. You may need to think about buying some maternity pants about now, as your belly is beginning to pop!
Your baby’s eyes and ears are moving into the right position and vocal cords begin to form. Bones are beginning to harden and movements are more deliberate. Your baby’s sex organs are now visible but can be difficult to determine via ultrasound at this gestation.
Read more about week 12 of pregnancy.
Pregnancy Week By Week: Week 13
This is the last week of the first trimester! All your pregnancy symptoms may fade in the next few weeks as you enter the easy second trimester. Your baby belly will keep growing and you may feel some aches or pulling sensations around the lower abdomen. The ligaments supporting your uterus are stretching to accommodate your growing baby.
By now your baby has kidneys and is passing urine, adding to the fluid in the amniotic sac. Movements are definitely increasing and some women become aware of them, especially if they have been pregnant before.
The important phase of development for your baby has been completed and from now your baby will continue to mature and grow, in preparation for birth.
Read more about week 13 of pregnancy.
Enjoy the second trimester – it’s usually the most favourite trimester for pregnant women. The bump is finally noticeable, but not too big and uncomfortable, you get the ‘glow’ and your risk of miscarriage has dropped dramatically. Your moods tend to be more settled and energy much better than in the first trimester – so we hope you enjoy your next 13 weeks.