you do not know every woman who has ever been pregnant, nor every experience a pregnant woman goes through since there are billions of women around the world.
Pregnacy is relatively the same for most.
The main difference between two women who are pregnant come from the country's culture (like these shithole that treat women as object) or the developpement of medicine, and from the health, the lifestyle and the personality of the mother.
For the culture i cant say much, but for the medicine diference it's actualy quite well documented.
The difference between women's pregancy due to their lifestyle, health and personaly are well know, and studied a lot all around the world.
Bitch who smoke, drink, party, do drugs, have a realy hard time with it, quite obviously because they are shitty human.
There are also people who have health issue do to their shitty personality, the most common being the 150kg whale (but you can also add extrem narcissist and egoistic people in this one), these people also have a hard time because they spend more time saying that the world is the root of their issue and not how they themself act. And the main reason they have a hard time is because they refuse to listen to what everyone know about pregnancy and dont want to change their way of life for the safety of their kids.
On the other hand most women live pregnancy nearly the same way, simply because with the most basic knowledge they will be able to deal with eveythings quite easily. If you take care of your health before your pregnancy then you wont have a real hard time.
You will have to deal with morning sickness, but they will barely affect you because you are healthy and you listened to you doc about what to do to make them pass.
The hardest part will be to be able to control your hormone that will fuck up your ability to make any kind of decision. These will make you want to eat random shit just because. This will also make it so you are extremely easily depressed and scared, but this can easily be deal with if you prepared before hand and have a good family surounding you. You will also be pissed at everyone for no reason.
The weight you take will not be a real issue of you take care of yourself, most women keep living normaly, even those who have a job or rise many kids alone. It will start hindering your life in the last 3 to 4 month, and even then any healthy woman will be alright. All you need to do is to listen to all the things your docs tell you to be carefull about.
The only real issue women who are healthy and took care of their kids can face during their pregnancy are suddent health and mental issue. The mental one are all kind of depression that happen at different time of the pregnancy. These are mainly due to their hormone having fun, they can all be dealt with relatively easily if the woman is inclined to listen to what the docs tell her instead of being stupidly stubborn. These can take a huge toll on the woman, but docs are accustomed to this do it's not realy an issue.
The suddent physical issue cant be prevented most of the time, but are nearly always cured at least in developped country. Some rare case can put the risk of the mother, the kid, or the two at risk, but in these case the docs will do their best until the end.
Saying that we cant understand pregnancy is like saying we cant understand puberty, it dont make sense.
Pregnancy is extremely normal and is something all healthy women will experiance, so humanity studied to for thousand of year to reduce the hardship and understand it.
Like i said, if and average joe like me can understand somethings as abstract and complex as astrophysics and thermodynamics there is no reason to not be able to understand pregnancy.
Also, i'm not rilled up. I'm just writing casualy and explaining things, because more and more people start to believe this weird things that pregnancy is some mystic things super hard to understand. And this is not a good thing to believe, because if men start to believe it then more and more of them will act as if they couldn't do anythings to help their wife.