yamuksigara

Well .... Have you read or maybe at school you were taught about wolf packs? or If you're like me who watched Teen Wolf I think I can explain it like that. It uses the same system as wolf packs : you have the leaders Alphas, the medium strength wolves that are betas and the lowest in strength and rights among wolves in the pack the omegas.
In omegaverse it uses basically the same system. Omegas can get pregnant naturally even if a man is an omega and in some omegaverse yaoi Alpha bite in the nape the omega and that makes the omega unable to have sex with someone else ( in theory actually there is an omegaverse about love between a beta and an omega and it wasn't that much of a problem .... Well it is ambiguos in that part....Well you can say it is open to interpretation how much the bite in the nape affects the omega) but the Alpha can have sex with many other partners even after he has bitten an Omega.
I think you can also read this http://www.mangago.zone/read-manga/abarenbo_honey/nbt/6d5913acc7b0dbb2/ChChapter_1/6/

Maybe this explains way better that me... and recommendations just search in tags with omegaverse the Attack of titan dj are AWESOME! and there are also many now.
http://www.mangago.zone/tag/omegaverse/

Hope it's helpful for you

I may be wrong, but it is an alternate universe that has a second genre, like the usual ones being female/male, but with alfa/beta/omega. The kink here is that even being male, if that one is an omega, he may become pregnant (Sorry, kinda of lazy to explain all of it, but you may read better here http://puppylover857.deviantart.com/journal/Omegaverse-Explanation-and-Guide-441250200 ).
Anyway, the ones I recommend are :
- Sayonara Koibito, Mata Kite Tomodachi
- Fan Service (Attack on Titan's DJ)
- B-Boy Omegabirth Anthology
And there are a pretty much others ╮(￣▽￣)╭

Thanks (⌒▽⌒)

Thank you for explaination it was really helpfull thank you so much (づ￣ ³￣)づ