Your pregnancy is an exciting time - but it can also be a confusing one.
Find out the most important things you need to know about the miracle inside of you! Amniotic fluid This cushions and protects your baby from temperature changes in the womb and is replenished every three to four hours (with a little help from your baby's urine!) Blastocyst Your unborn baby reaches this stage as your egg enters the womb and begins to implant, which is around a week after fertilisation.
The backbone, spinal column and nervous system are forming now.
Chorion This is the outer layer of the amniotic sac (the bag of water that encloses and protects your baby in the womb).
Dreams Research has shown that unborn babies have periods of REM sleep, where their eyes move rapidly under the eyelids.
Some scientists believe this shows that your baby is dreaming.
Embryo Your baby is referred to as an embryo from implantation up to the 10th week of your pregnancy.
Foetus Your baby moves on to this stage at 10 weeks.
He's around 1 inch long, his fingers and toes are forming and his brain waves can be measured.
Gender High-definition pregnancy scans can now reveal if your baby is a girl or a boy as early as 11 weeks.
Hearing Your baby's ears begin to form at around week eight of your pregnancy.
By week 18 they can hear the sounds of your body, and by the 25th they can hear your voice outside the womb.
Implantation Around seven days after you ovulate, the fertilised egg that will become your baby enters your womb and burrows into the lining, causing the placenta to start developing.
Jawbone Your baby's jawbone is formed by around week 10 and already contains the buds for all those tiny milk teeth.
Kicks Your baby gets a kick out of you, and this stage of pregnancy can be really uncomfortable at times! Although you might get the odd boot in the bladder, it's reassuring to feel those tiny feet poking you.
Lanugo This fine, downy hair covers your baby's skin in the womb.
It wears off in later pregnancy.
Meconium This greenish-black tar-like substance is basically your baby's poo, made up of dead skin cells he's ingested during the pregnancy from swallowing amniotic fluid.
He'll fill his nappy with this in the first few days after he's born.
Neural tube Your baby's neural tube begins to form three weeks after fertilisation and will eventually develop into his brain and spinal cord.
At birth, your baby's brain will have 100 billion cells! Ovaries If your unborn baby is a girl, at birth her ovaries will already hold all the eggs her body will ever produce.
Placenta Your baby's life support system: this transfers nutrients and oxygen to your baby via the umbilical cord during the pregnancy and processes his waste products.
Quickening You'll notice your baby's first movements by around week 18: even earlier if it's not your first.
Starting as a flutter, they graduate into hard kicks and somersaults! Reflexes As early as week five of your pregnancy, your baby's developing reflexes, from those first tiny kicks to more sophisticated frowns and grimaces.
By week 32 of your pregnancy, your baby's suck-and-swallow reflex, which is vital for survival, is perfected.
Surfactant Your baby's lungs manufacture this substance towards the end of pregnancy.
It covers the inner lining of the air sacs in his lungs and allows them to expand as your little one breathes.
Thumb-sucking A baby frequently touches his face because the skin is very sensitive, which may be why his thumb eventually finds his mouth.
Many ultrasound scans reveal babies sucking their thumbs.
Umbilical cord This is your baby's lifeline.
Around 2ft long, it connects them to the placenta and contains two arteries and a vein through which they receive oxygen and nutrients.
Vernix This is a waxy substance that protects the skin from being waterlogged by amniotic fluid.
Wharton's jelly This mucus makes the umbilical cord supple enough to withstand the twisting of your lively baby.
X-chromosome Your egg is X-chromosome (female) and your partner produces X- and Y- (male) chromosome sperm.
If an X sperm reaches the egg first, you'll conceive a girl.
But if a Y sperm wins, you'll have a boy.
Yawning Although your unborn baby doesn't feel tired as we know it, ultrasound scans have shown babies yawning - as if they're doing all the hard work! Zygote One of your baby-to-be's earliest developmental stages, as your egg makes its way down the fallopian tube.
Find out the most important things you need to know about the miracle inside of you! Amniotic fluid This cushions and protects your baby from temperature changes in the womb and is replenished every three to four hours (with a little help from your baby's urine!) Blastocyst Your unborn baby reaches this stage as your egg enters the womb and begins to implant, which is around a week after fertilisation.
The backbone, spinal column and nervous system are forming now.
Chorion This is the outer layer of the amniotic sac (the bag of water that encloses and protects your baby in the womb).
Dreams Research has shown that unborn babies have periods of REM sleep, where their eyes move rapidly under the eyelids.
Some scientists believe this shows that your baby is dreaming.
Embryo Your baby is referred to as an embryo from implantation up to the 10th week of your pregnancy.
Foetus Your baby moves on to this stage at 10 weeks.
He's around 1 inch long, his fingers and toes are forming and his brain waves can be measured.
Gender High-definition pregnancy scans can now reveal if your baby is a girl or a boy as early as 11 weeks.
Hearing Your baby's ears begin to form at around week eight of your pregnancy.
By week 18 they can hear the sounds of your body, and by the 25th they can hear your voice outside the womb.
Implantation Around seven days after you ovulate, the fertilised egg that will become your baby enters your womb and burrows into the lining, causing the placenta to start developing.
Jawbone Your baby's jawbone is formed by around week 10 and already contains the buds for all those tiny milk teeth.
Kicks Your baby gets a kick out of you, and this stage of pregnancy can be really uncomfortable at times! Although you might get the odd boot in the bladder, it's reassuring to feel those tiny feet poking you.
Lanugo This fine, downy hair covers your baby's skin in the womb.
It wears off in later pregnancy.
Meconium This greenish-black tar-like substance is basically your baby's poo, made up of dead skin cells he's ingested during the pregnancy from swallowing amniotic fluid.
He'll fill his nappy with this in the first few days after he's born.
Neural tube Your baby's neural tube begins to form three weeks after fertilisation and will eventually develop into his brain and spinal cord.
At birth, your baby's brain will have 100 billion cells! Ovaries If your unborn baby is a girl, at birth her ovaries will already hold all the eggs her body will ever produce.
Placenta Your baby's life support system: this transfers nutrients and oxygen to your baby via the umbilical cord during the pregnancy and processes his waste products.
Quickening You'll notice your baby's first movements by around week 18: even earlier if it's not your first.
Starting as a flutter, they graduate into hard kicks and somersaults! Reflexes As early as week five of your pregnancy, your baby's developing reflexes, from those first tiny kicks to more sophisticated frowns and grimaces.
By week 32 of your pregnancy, your baby's suck-and-swallow reflex, which is vital for survival, is perfected.
Surfactant Your baby's lungs manufacture this substance towards the end of pregnancy.
It covers the inner lining of the air sacs in his lungs and allows them to expand as your little one breathes.
Thumb-sucking A baby frequently touches his face because the skin is very sensitive, which may be why his thumb eventually finds his mouth.
Many ultrasound scans reveal babies sucking their thumbs.
Umbilical cord This is your baby's lifeline.
Around 2ft long, it connects them to the placenta and contains two arteries and a vein through which they receive oxygen and nutrients.
Vernix This is a waxy substance that protects the skin from being waterlogged by amniotic fluid.
Wharton's jelly This mucus makes the umbilical cord supple enough to withstand the twisting of your lively baby.
X-chromosome Your egg is X-chromosome (female) and your partner produces X- and Y- (male) chromosome sperm.
If an X sperm reaches the egg first, you'll conceive a girl.
But if a Y sperm wins, you'll have a boy.
Yawning Although your unborn baby doesn't feel tired as we know it, ultrasound scans have shown babies yawning - as if they're doing all the hard work! Zygote One of your baby-to-be's earliest developmental stages, as your egg makes its way down the fallopian tube.