Disclaimer #1: I’ve said it before and I’ll say it again - I don’t write fics. I don’t know, maybe you guys think I have a secret AO3 account and fit my own fics within the recs I do but I really, really don’t :D
Disclaimer #2: wow, the list of the requirements you have is… impressive (although at the same time really normal). What I ask is for you guys to remember that writing fics is difficult. I’m friends with people who write fics and I think they’re massively talented but I still hear form them how much they struggle. It’s understandable to want quality, of course, but while reading a fic it’s worth to put on “a real human being who is their own person, has their own ups and downs, who is still growing as a person and most importantly as an author wrote that” glasses. It’s normal that things (fics) have imperfections but that doesn’t mean they’re not great Being an author, being an artist, I believe, is an infinite work in progress. [curls protectively around fanfic writers]
Disclaimer #3: you never specified what pairing you meant but someone else asked for sterek so I’m going to assume you asked for sterek too. If not then let me know.
Having said that let me present you with a list of mpreg fics I’ve read and which, to greater or lesser degree, fulfil your requirements.