I mean everyone already told you the same thing, but all i gotta say is that it's not worth doing something like this. You'll grow up to think that this is acceptable and it's not. If you were in college and doing something like this, they wouldn't think twice about kicking you out.
I know that they're a-lot of Katsuki x Preg Reader books, but there is a BIG difference between having the same idea and just copying someones work and labeling that as yours.
Here in New York, that's illegal, so if you lived in New York you would technically be breaking the law even though it's not an actual crime. Killing someone is a crime while plagiarism is just plain taking a person's hard work and claiming it as your own.
So please please PLEASE think before you do, because things like this come with consequences.