The sleep deprivation is way more of an issue than poop. My 9 year old woke me up at 3 in the morning, because she had a nightmare this was after the two year old decided she could only sleep in daddy’s bed and before the 4 year old peed in her bed at 5am. I tolerate it because I actually want kids, but it is a lot of work.
You also have to consider any special needs/ behavioural problems that you or your partner had as a child, because a lot of those are hereditary. Not to mention they will get sick from all the childhood diseases and they’re not good about holding their vomit til they get to the bathroom. I have been puked on several times.
Then there’s the financial problems. If you’re tall your kid will blow through clothing really quick. My eldest is currently wearing adult XS clothes. They don’t eat much, but you’ll end up not being very adventurous in the kitchen because kids don’t eat nice food. If you are in the states daycare is pretty pricey. I know of at least one postdoc who quit her academic career because her entire paycheck wasn’t enough to cover the cost of daycare. If you live up north, winter clothing is really expensive. In Norway, a set of wool underwear will cost over 40 USD and you’re talking about the same for a cheap set of winter boots and about 100 USD for a snowsuit. These need to be replaced often.
All of this is worth it if you want kids. But you need to talk to your partner. If you don’t agree on weather or not you want children then you need to end things, because either way one of you will grow to resent the other. I’ve seen it happen many times either you are forced to give up your life for 18 years or he’s forced to give up on starting a family. Neither of those things are fair. I could give you articles but they’re all basically people’s opinions anyway. And the decision needs to be based on what you want for your life, not what someone else thinks.