But there's something else that also gets flipped upside down: our wardrobes.
Yes, with a growing tum comes a necessary change in what to wear, and while it can be hard to accept that you can't just slide into your favourite jeans as easily as we used to, there's a whole world of possibilities in the clothing department that will guarantee you comfort and style during your pregnancy - and even those weeks and months after.
So where to start? You've probably raked through all the maternity clothing websites, visited the local outlets to spy out their chicest baggy wear, and gone into a mild panic about how to dress your burgeoning bump without taking out a loan or looking just plain frumpy.
But fear not - there are certain styles to look out for when it comes to dressing your bump, and you don't have to look far to find them, or spend a fortune.
Keep scrolling to see our favourite maternity styles and hot tips on where to buy them!
A peplum style, in which a strip of ruffled or flared fabric is added to the bottom of a top, has long been a staple in maternity wear, and you don't have to look far to see why. The style is flattering, comfortable and smart enough for work, but can be casualed-down for weekend wear. Not to mention it makes your bump look adorable.
These are a no-brainer - and a good wardrobe investment as some styles will go well beyond pregnancy.
As we head into summer, a maxi dress should be a staple in any expecting mum's wardrobe. They're loose fitting, breezy and you can get creative with prints!
And while we've highlighted one from a maternity range below, there are heaps of styles you can find in general non-maternity fashion that will take you all the way through your pregnancy and even post birth.
Owning the perfect t-shirt is a must whether you're pregnant or not, but don't be afraid to wear them about 10 times more during your expecting months! In our opinion, the slouchier, the better.
The below plain tee from Cotton On is perfect in black – you can dress it up with some striking gold jewellery, a black skirt or pants and kitten heels, or dress it down with your favourite pair of jeans (yes, you can still wear jeans when pregnant! See below...).
Leggings are incredibly comfortable at the best of times, but they're everything and more when it comes to pregnancy. Plus they will be the most versatile piece in your fashion wardrobe.
They don't have to be just at-home wear - they can be dressed up and down making them perfect for every occasion - believe us! Team with a t-shirt and some runners (like below) and they're perfect for running errands, going for a walk or lounging around home. Throw on a longer-line shirt or top, and slip on some ballet flats or boots, and these leggings become smart, going-out, wear.
Not only will a belt help to break up an outfit, but they can also really help to give your tired back some support.
If you're wearing a loose dress or tee, simply place a belt at the top of your tummy. It'll not only give you some shape, but your bump will look adorable!
In terms of styles, this one's pretty open to your own preference. A thick belt will provide you with plenty of back support, while a thin one, like the below style from Sportsgirl, will complement a flowing maxi-dress for a summertime barbecue.
Ruching on a dress, tee or even swimwear can be both chic and practical when it comes to dressing your bump.
Often including some super stretchy elastic to give the ruffled ruching effect, this style of clothing is perfect as your tummy grows – your ruched frock or top will stretch with you!
We have the royals to thank for making this style look flawlessly chic. If you're pregnant during the cooler months, investing in a nice woollen pea coat will serve its purpose in more ways than one.
The pea coat style, which is typically less shaped than a fitted winter jacket, is perfect for a growing bump – Kate Middleton is case and point!
Pregnancy doesn't mean you have to forgo your favourite denims!
There are heaps of maternity jeans around - and they come with a customised waist that comfortably caters for your growing bump. You can pretty well find what ever style you like to wear, from skinny to boyfriend and even flares.