i know this wasn’t really what you were asking for and nothing to do with omegaverse but there’s Kedamono Arashi that’s a short mpreg manga with sequels following it. not exactly what you wanted but it’s still cute
or maybe like Habibi's Rabbits
https://www.mangago.zone/read-manga/surge_looking_for_you/
The baby at the end was worth the story. I don’t typically like babies but this little guy was too cute.
Melting into You https://www.mangago.zone/read-manga/melting_into_you_1/
Kiss me, Liar https://www.mangago.zone/read-manga/kiss_me_liar/
How to Snag an Alpha https://www.mangago.zone/read-manga/how_to_chase_an_alpha/
Love is an Illusion https://www.mangago.zone/read-manga/love_is_an_illusion/
Struggle https://www.mangago.zone/read-manga/struggle_1/
One of them actually has a kid pretty early on, but they break up due to a misunderstanding, so the ML isn’t even aware he had a kid until later on.
Please and ty very much, or well any good omega verse yaoi that actually shows the baby at the end