Alpha usually get pregnant with another Alpha. But it would take longer getting pregnant with a Beta and even more with Omega. But authors would change everything to their likings so everything can happen. Also in another omegaverse the male who gave birth to his kid called him father, while in the other omegaverse mother. Again it depends on the authors taste.
For better understanding best to read this: (But take note that every author may change the rules of the world they create. But this the most common)
http://www.mangago.me/read-manga/abarenbo_honey/nbt/6d5913acc7b0dbb2/ChChapter_1/6/
Also if you like you can follow my OMEGAVERSE LIST as I'd been following lots of them (also not available here that unfortunately can't share):
http://www.mangago.me/home/mangalist/210068/
Either is possible, though i believe in this case, the one who gave birth was his mother.
in the omegaverse either sex can give birth because both sexes have all the necessary parts. the birthrate for alphas is very low but when they procreate with an omega the chances are higher because omegas are very fertile in general. though in this case i believe the alpha mother gave birth so the chances were lower. I suspect fated pairs also have increased chances of procreation.
There are more omegaverse stories out there that are not on my list.
http://www.mangago.me/home/mangalist/210068/
(I've been reading more in another language. Others only available in special app/website)
Even more omegaverse are in manhwa available that are also not here on Mangago.
I like omegaverse though some did get on my nerve LOL.
*But seeing to female parents is quite rare. Even more having Omega as Seme. (This the only one that I know of Omega being a Seme to Alpha: http://www.mangago.me/read-manga/boku_no_high_spec_kareshi_sama/ )
First omegaverse I remembered with two female as parents is
the parent of omega in http://www.mangago.me/read-manga/kasegimasen_kara/ I can't remember how many I reread this one but its so cute the other one its just one CH that get translated the parent of the alpha though I reread the raw so many times. http://www.mangago.me/read-manga/nyaa_to_nakukara_aishiteyo/ these two manga its in your list
Ah I remember now, thnks. Been reeding so many manga daily in different languages that I forgot lots of them. (Most of time need to reread to remember the plot again. But it's worth rereading hehe)
About sites other than hear (Manga/Manhwa/Manhua not available on this site):
> WebComics (Need to dl app from Google play store)
> Line Webtoons (I recommend: Our Omega Leadernim!,)
> Qvfamma blogspot (It's all in Spanish. They translate lots of omegaverse not yet translated in English)
> And other individual platforms such as FB.
Gyus i didnt understand onething
Chikas mother is she or he?
I mean the dad is omega so who did give birth?
Lol