Will start by saying that no matter what you won't regret it and it will be worth it but it is a huge change that takes adjustment. I think no matter how hard you try to prepare, it is a really big shock to the system.

Firstly, superficial maybe but pregnancy changes your body. I might still 55kg but there are stretch marks, my curves are softer (ha being kind to myself describing it that way) and my breasts are not as perky as before. Also depending on your birth there can be changes to other areas etc. As an upside, I think pregnancy makes you appreciate your body so much more; I am in awe of it and find the imperfections to be kind of beautiful now.

Secondly, somebody relying on you 100% all of the time is draining; emotionally and physically. As PZ said, you can't take time off on a whim and you will probably crave personal space at times. Being spontaneous is a lot harder. Even getting a shower or hot meal will be difficult at first, let alone a meal out etc. You lose the freedom to sleep in, take off for a quick weekend away, just sit and stare at a wall whenever you wish.

Nappies are not fun. Maybe there is somebody, somewhere who enjoys that aspect but yeah, ick! And they get worse as they grow and progress onto solids. You will also get thrown up on a bit or a lot, I once had some land in my mouth.

Basically, you will forever feel vulnerable. As someone mentioned, when they are sick you will long for the day when it was you that was sick. Even just the prospect of them maybe, possibly coming down with something small will have you worrying; the tiniest sneeze or temperature change will proberly have you jumpy at first. Then they start moving and yeah, toddlers can be clumsy which is hard to watch!

Toddlers like to share their food and can be pretty offended if you do not accept their slobbered on crusts etc. It can be kind of gross. They also like to backwash in your cup! They might also draw on your favourite outfit or rip your favourite book.

But really, all of that just doesn't even seem important, being a parent is amazing; warts and all. Except the nappy thing, I will willingly accept a nappy fairy to deal with those!