Zetsurin Alpha ni ai O Koe
Ch.1-5 - An omega girl gets raped by an alpha as a young girl and thinks she's in love (as does the story, but I think that's BS). As an older woman and oiran (Japanese prostitute), she finally meets him again. Trigger warnings: rape, sex trafficking. Ch.6-9 - A tough girl omega and wimpy boy alpha are childhood friends who separate after her first heat and are finally reunited as adults. No trigger warnings. Ch.10-11 - In an animal omegaverse world, alphas are expected to have many wives so they can bear a lot of children, and a goat beta girl can't admit she loves her cat alpha childhood friend because she wants him all to herself. No trigger warnings, except secondhand embarrassment.
Koi Suru Mae ni, Amai Hatsujou. - Shachou to Unmei no Omega
Uiko goes to an alpha/omega salon to deal with her heat and ends up paired with her boss, though she doesn't know it.
A Sadistic Cop Won't Let Go of His Destined Omega: I'll Teach You How to Have Sex in Heat
Ichika is a romance writer who's editor suggest she goes to a host club to get more experience for her writing, and she's almost date-raped until the police bust in and police officer Jin ends up taking care of her heat, instead. Turns out, they're a fated pair. Not particularly interesting straight omegaverse smut. Trigger warnings: drug(aphrodisiac), dubcon.
Hatsujou Suru Unmei ~Eriito Alpha No Risei Ga Genkai~